Planarizing material and planarizing method

A planarizing material comprising a resin capable of having its practical temperature for a planarizing step set at a level lower than 200.degree. C., and a melamine-type heat-curing agent and/or an epoxy-type heat-curing agent.

BACKGROUND OF THE INVENTION 
1. Field of the Invention The present invention relates to a planarizing 
material and a planarizing method useful for the production of charge 
coupled devices, liquid crystal display devices and semiconductor 
integrated circuits devices. More particularly, it relates to a 
planarizing material which is capable of presenting a high level of 
flatness and which satisfies the requirements for excellent heat 
durability, solvent resistance and transparency, and a planarizing method 
which is capable of providing a high level of flatness by a simple 
operation in a step of planarizing a substrate having surface 
irreguralities. 
2. Discussion of Background 
Each of the processes for producing charge coupled devices, liquid crystal 
display devices and semiconductor integrated circuit devices includes a 
step of multi- layering by lamination of elements although the purpose may 
be different. Therefore, the technique for flattening or planarizing a 
substrate having surface irreguralities is a technically important subject 
common to the respective processes. 
A solid-state image pick-up device has a structure wherein two or three 
color filter layers are laminated on an element having a photodiode formed 
on a silicon substrate, and a surface protective film is further formed 
thereon. For high densification of picture elements of a solid-state image 
pick-up device, it is required that color filter layers having the size 
and shape controlled to a high level are formed and laminated at a high 
density. In an on-chip method which has been most commonly employed 
recently, planarization of an element as the lowermost layer and 
planarization of the respective color filter layers are essential and 
constitute very important steps for the production. 
In the case of a liquid crystal display device, a color filter layer, a 
protective film layer, an ITO film and an orientation film are 
sequentially formed on a transparent substrate to form a colored liquid 
display device. However, if there exists a stepped portion in the colored 
liquid crystal device thus prepared, when a liquid crystal compound is 
sandwiched between a pair of the transparent substrates, there will be a 
difference (irreguralities) in the thickness of the liquid crystal between 
the pair of the substrates. As a result, there will be a color fading 
phenomenon or the like due to retardation or orientation failure of the 
liquid crystal. Accordingly, also in the field for the production of 
liquid crystal display devices, planarization of the respective layers is 
a technically important subject. 
Further, in the production of a semiconductor integrated circuit device, it 
is required to sequentially laminate an insulating layer and a conductive 
layer from its structural nature as is well known. However, in recent 
years, as the number of conductive layers has increased to two or three 
layers, the level difference of the conductive layers has become acute, 
whereby disconnection, short circuitting or the like is likely to result 
at intersections of conductive layers and thus makes the laminated 
structure substantially difficult. Therefore, it is essential to level the 
surface of the insulating layer prior to forming a conductive layer in 
order to prevent such disconnection, short circuitting or the like. Thus, 
establishment of a planarizing technique is an important subject also in 
this filed. 
The following various methods have been proposed to solve problems in such 
a planarizing step common to various fields. 
1) A method in which as a planarizing layer on a stepped portion, a 
polyglycidyl methacrylate (PGMA) type or a modified PGMA type which is 
usually transparent in a visible light region and which is curable by heat 
or light, is used. 
2) A plasma etching method used in the field of the production of liquid 
crystal display devices, wherein a planarizing material is flattened by 
plasma etching (Japanese Unexamined Patent Publication No. 147232/1986). 
3) A method wherein a material having a relatively low heat deformation 
temperature such as polystyrene or its derivative having a molecular 
weight of about 10,000, is spin-coated on a stepped portion and heated to 
a temperature higher than the heat deformation temperature (e.g. 
200.degree. C.) to let the material flow to form a planarized organic 
resin surface, which is then cured by ultraviolet rays, and further 
subjected to dry etching to obtain a flat surface (Japanese Unexamined 
Patent Publication No. 225526/1984). 4) A method wherein the ultraviolet 
curing step in the above-mentioned method can be simplified by conducting 
heat-curing by means of a polymer having a low molecular weight having 
heat-curable functional groups introduced therein (Japanese Unexamined 
Patent Publication No. 227407/1990). 
On the other hand, reflecting high densification of picture elemnts and 
high integration of devices in recent years, an attention has been drawn 
to a halation-preventing technique as an important function required for 
the material, as well as such a planarizing technique. Each of the 
processes for the production of the above-mentioned devices, include a 
step of applying fine working on a laminated planarized material by means 
of photolithography. The halation means spreading of light caused by 
reflection from a substrate, which takes place in such a photolithography 
step, for example, when the substrate has a glossy metal portion (such as 
aluminum, chromium, platinum or nickel). At the site where such halation 
(spread of light) has taken place, the region of a photosensitive material 
where no sensitization is desired, is sensitized, thus leading to a 
problem that the resolution will be remarkably impaired. Accordingly, in 
the photolithography step in the field of the production of a highly 
densified picture element device or a highly integrated device where a 
high level of resolution is required, a certain measure is required 
against halation in such a photolithography step. To solve such problems 
of halation, the following methods have been proposed. 
1) In a process for the production of semiconductors, a method of directly 
incorporating to a photosensitive material, a light-absorbing agent 
capable of absorbing a certain specific wavelength corresponding to the 
wavelength for exposure, such as an organic dye as a halation-preventive 
agent (Japanese Unexamined Patent Publication No. 37562/1976). 
2) In the field of the production of charge coupled devices and liquid 
crystal display devices, a method of forming a layer having a 
halation-preventive agent incorporated, as a planarizing layer beneath a 
color filter layer (Japanese Unexamined Patent Publication No. 
142606/1989). 
3) Also in the field of the production of charge coupled devices and liquid 
crystal display devices, a method of using a polymer light-absorbing agent 
or oligomer light-absorbing agent, having a light-absorbing agent capable 
of absorbing light of a certain specific wavelength corresponding to the 
wavelength for exposure incorporated as a halation-preventive agent to a 
polymer or oligomer. 
With respect to the above-mentioned methods for planarization, however, in 
the case where an organic substance is spin-coated as in the method 1), it 
is usually very difficult to form a uniform coating film over the 
irreguralities on the substrate and to completely level the surface of the 
substrate. Accordingly, it is presently common to adopt a method in which 
the viscosity of the planarizing material is controlled by reducing the 
concentration of the resin or reducing the molecular weight. However, by 
such a method, it is difficult to obtain a sufficient film thickness for 
planarization or to obtain a satisfactory film quality uniformly. Further, 
reflecting the requirements in recent years for high densification in each 
of charge coupled devices, liquid crystal display devices and 
semiconductor integrated circuit devices, it is required by a planarizing 
process to completely fill a planarizing material into fine spaces between 
elements, and such an operation will be difficult by this method. The 
method 2) requires an etching step and thus has a problem that the process 
will be cumbersome and the productivity is poor. The method 3) has a 
problem that when applied to a production process, this method requires 
cumbersome steps such as a ultraviolet curing step and an etching step, 
and thus the productivity is poor. Further, to attain adequate flatness by 
the planarizing step of heating and fluidizing a resin, heating at a high 
temperature of a level of 200.degree. C. is required. Therefore, it is 
likely to bring about an adverse effect such as deterioration of the 
transparency of a color filter or discoloration of the dye especially in 
the cases of a solid-state image pick-up device or a liquid crystal 
display device. Therefore, this method has a problem that it is hardly 
applicable to such a field. The method 4) requires a long period of time 
for planarization by heating and fluidizing. Besides, it requires a 
heat-curing step at a high temperature, separate from the planarizing step 
by heating and fluidizing, and thus has a problem that the process is 
cumbersome, and the productivity is poor. Further, also in this method, a 
high temperature is required in a step of heating and fluidizing the 
planarizing material or in the heat-curing step, and thus it is difficult 
to apply this method to a field of the production of charge coupled 
devices or liquid crystal display devices. On the other hand, with respect 
to the halation-preventing technology, the method 1) may be useful for the 
process for the production of semiconductor integrated circuit devices, 
but in the production of charge coupled devices and liquid crystal display 
devices where a natural protein is employed as a coloring base material 
for a color filter, a method of directly incorporating an organic dye to 
the color filter is not desirable from the nature of the color filter, and 
it is difficult to apply this method to such a field. In the method 2), 
most of the halation-preventive agent is likely to be evaporated or 
sublimed due to the heat applied in the curing step of the planarizing 
layer, whereby the expected effects can not adequately be obtained. 
Further, also by the method 3) proposed for the purpose of suppressing 
such evaporation or sublimation, the halation-preventive agent has a 
difficulty in the compatibility with the base polymer for the planarizing 
material or with the curing agent, and thus, this method also has a 
problem that it is difficult to directly incorporate the 
halation-preventive agent to the polymer or the oligomer. 
Thus, heretofore, there has been no material which fully satisfies basic 
properties such as heat durability, solvent resistance and transparency 
required for charge coupled devices, liquid crystal display devices and 
semiconductor integrated circuit devices, respectively, and which has a 
high level of a planarizing property and is applicable to all the fields 
of producing charge coupled devices, liquid crystal display devices and 
semiconductor integrated circuit devices. Likewise, there has been no 
planarizing method which provides a high level of flatness by a simple and 
efficient step. 
SUMMARY OF THE INVENTION 
The present invention has been made in view of the above problems, and it 
is an object of the present invention to provide a planarizing material 
which presents a high level of flatness to a substrate having surface 
irreguralities in a planarizing process, which is an important technical 
subject common to the production of charge coupled devices, liquid crystal 
display devices and semiconductor integrated circuit devices and which 
satisfies the basic properties such as heat durability, solvent resistance 
and transparency required for such devices and is applicable to all of the 
above-mentioned fields. 
It is another object of the present invention to provide a planarizing 
material having a function to effectively prevent halation. 
A further object of the present invention is to provide a planarizing 
method, whereby various post-treatment steps required by conventional 
methods can be omitted so that the cumbersomeness of the process can be 
reduced and the productivity can be improved. 
The present inventors have conducted extensive researches to attain the 
above objects. As a result, they have found that a high level of flatness 
can be obtained by a simple process by using a planarizing material 
comprising, as the basic constituents, a resin capable of having its 
practical temperature for a planarizing step set at a level lower than 
200.degree. C. and a heat-curing agent and if necessary, by adding a 
prescribed halation-preventive agent and/or a curing catalyst to the 
planarizing material. Further, they have found that when the 
halation-preventive agent or the curing catalyst to be incorporated has a 
functional group reactive for an addition reaction with at least one of 
said resin, said heat-curing agent, said halation-preventive agent and 
said curing catalyst, the evaporation, sublimation or migration during the 
heating can almost completely be prevented, and a high level of effects 
can be obtained by incorporation of a small amount of the 
halation-preventive agent or the curing catalyst. The present invention 
has been accomplished on the basis of these discoveries. 
The present invention provides a planarizing material comprising a resin 
capable of having its practical temperature for a planarizing step set at 
a level lower than 200.degree. C., and a melamine-type heat-curing agent 
and/or an epoxy-type heat-curing agent.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Now, the present invention will be described in detail. 
The resin capable of having its practical temperature for a planarizing 
step set at a level lower than 200.degree. C. may, for example, be an 
acrylic resin, a styrene resin, or a polyvinyl alcohol or its derivative, 
which can be obtained by adjusting the glass transition temperature (TG) 
or the molecular weight of the resin. Among them, an acrylic resin is 
preferred for a reason such that various properties such as transparency 
and heat durability of the cured coating film are excellent, which are 
important especially in the filed of producing charge coupled devices and 
liquid crystal display devices. Further, an acrylic resin comprising 
structural units of the following formula (1), is preferred, since it has 
a functional group reactive with a heat-curing agent for an effective 
crosslinking reaction: 
##STR1## 
wherein each of R.sub.1, R.sub.2 and R.sub.3 is hydrogen or a methyl 
group, each of A.sub.1, A.sub.2 and A.sub.3 is OB.sub.1 or NB.sub.2 
B.sub.3, wherein each of B.sub.1, B.sub.2 and B.sub.3 is hydrogen, a 
C.sub.1-6 alkyl, alkenyl or hydroxyalkyl group, a C.sub.2-12 epoxy group, 
a C.sub.6-12 aryl group or a C.sub.7-12 aralkyl group, and each of x, y 
and z is a positive number inclusive of 0 and they satisfy the following 
formulas: 
EQU 0.ltoreq.x/(x+y+z).ltoreq.1 
EQU 0.ltoreq.y/(x+y+z).ltoreq.1 
EQU 0.ltoreq.z/(x+y+z).ltoreq.1 
In the above formula, the alkyl group for B.sub.1 to B.sub.3 may, for 
example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl 
group, a n-butyl group, an isobutyl group, a t-butyl group, a n-amyl 
group, an isoamyl group, a n-hexyl group or a cyclohexyl group; the epoxy 
group may, for example, be a glycidylepoxy group such as an ethylenoxide 
group or a propylenoxide group, or an alicyclic epoxy group such as a 
cyclohexenoxide group, a cyclopentenoxide group or a tricyclodecenoxide 
group; the aryl group may, for example, be a phenyl group, a tolyl group, 
a xylyl group, an ethylphenyl group or a naphthyl group and some of 
hydrogen atoms on an aromatic ring in the aryl group may be substituted by 
e.g. a halogen atom such as chlorine or bromine, a nitro group or a cyano 
group. Further, the aralkyl group may, for example, be a benzyl group or a 
phenetyl group, and some of hydrogen atoms on an aromatic ring of the 
aralkyl group may be substituted by e.g. a halogen atom such as chlroine 
or bromine, a nitro group or a cyano group. 
Here, a planarizing step means a step of heat-curing as well as heating and 
fluidizing after coating a prescribed planarizing material to form a film 
on a substrate having surface irrefuralities. 
With the planarizing material in the present invention, the fluidity under 
heating of the resin capable of having its practical temperature required 
for a planarizing step set at a level lower than 200.degree. C., varies 
depending upon the configuration and the size of the stepped portion to be 
planarized. The fluidity under heating of this resin can be adjusted by 
controlling the glass transition temperature (Tg) of the respective 
components constituting the resin and the molecular weight of the resin. 
Accordingly, the molecular weight of the resin capable of having its 
practical temperature for a planarizing step set at a level lower than 
200.degree. C., is not particularly limited, in the present invention. For 
example, the molecular weight may be within a range of from a few hundred 
to about 500,000. However, taking into consideration the physical 
properties such as heat durability and solvent resistance of the cured 
coating film and preferred temperature and time for heating and 
fluidizing, the molecular weight is preferably from 1,000 to 100,000. 
Further, at a site where stricter flatness is required, the molecular 
weight is particularly preferably from 1,000 to 50,000 in order to obtain 
good fluidity under heating of the resin, while maintaining the desired 
physical properties of the cured coating film. 
In the present invention, the resin capable of having its practical 
temperature for a planarizing step set at a level lower than 200.degree. 
C., can be obtained by selecting a monomer from e.g. (meth)acrylic acid, 
and a (meth)acrylate, (meth)acrylamide, an N-substituted (meth)acrylamide 
and styrene taking the glass transition temperature of the obtained resin 
into consideration and by solution radical (co)polymerizing the polymer in 
accordance with a conventional method while controlling the molecular 
weight. For the planarizing material in the present invention, it is 
necessary to employ a melamine-type heat-curing agent and/or an epoxy-type 
heat-curing agent in order to impart various physical properties to the 
cured film such as solvent resistance and cracking durability required in 
the field of producing the respective devices. 
The melamine-type heat-curing agent may, for example, be methylolmelamine, 
a partially alkyl-etherified melamine, a completely alkyl-etherified 
melamine, a partially alkyl-etherified benzoguanamine, a completely 
alkyl-etherified benzoguanamine, a mixed alkyl-etherified melamine or 
mixed alkyl-etherified benzoguanamine having a plurality of alkyl groups 
introduced at optional proportions. Especially when the resin capable of 
having its practical temperature for a planarizing step set at a level 
lower than 200.degree. C., is an acrylic resin comprising structural units 
of the formula (1), it is preferred to employ a melamine-type heat-curing 
agent comprising structural units of the following formula (2) in order to 
improve the compatibility and the curing reactivity with the acrylic 
resin: 
##STR2## 
wherein Y is --NX.sub.5 X.sub.6 or a phenyl group, and each of X.sub.1 to 
X.sub.6 is hydrogen or --CH.sub.2 OZ, wherein Z is hydrogen or a C.sub.1-5 
alkyl group. 
The alkyl group for Z in the above formula may, for example, be a methyl 
group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl 
group, an isobutyl group, a t-butyl group, a n-amyl group or an isoamyl 
group. 
The melamine-type heat-curing agent comprising the structural units of the 
formula (2) includes, for example, a methylolmelamine such as 
trimethylolmelamine or hexamethylolmelamine, a partially alkyl-etherified 
melamine such as trimethoxymethylmelamine, tripropoxymethylmelamine or 
tributoxymethylmelamine, a completely alkyl-etherified melamine such as 
hexamethoxymethylmelamine, hexapropoxymethylmelamine or 
hexabutoxymethylmelamine, a partially alkyl-etherified benzoguanamine such 
as dimethoxymethylbenzoguanamine or dibutoxymethylbenzoguanamine, a 
completely alkyl-etherified benzoguanamine such as 
tetramethoxymethylbenzoguanamine or tetrabutoxymethylbenzoguanmine, and a 
mixed alkyl-etherified melamine or mixed alkyl-etherified guanamine having 
a plurality of alkyl groups such as a methyl group and a butyl group 
introduced at optional proportions into melamine or guanamine. 
The epoxy-type heat-curing agent is not particularly restricted, so long as 
it is an epoxy-type heat-curing agent composed of one or more compounds 
having at least one epoxy group, on average, per molecule. For example, a 
glycidyl ether type may, for example, be n-butylglycidyl ether, 
2-ethoxyhexylglycidyl ether, phenylglycidyl ether, allylglycidyl ether, 
ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 
neopentyl glycol diglycidyl ether, glycerol polyglycidyl ether or sorbitol 
polyglycidyl ether; a glycidyl ester type may, for example, be diglycidyl 
adipate or diglycidyl o-phthalate; and an arycyclic epoxy may, for 
example, be 3,4-epoxycyclohexylmethyl(4,3-epoxycyclohexane) carboxylate, 
3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexane 
carboxylate, bis(3,4-epoxy-6-methylcyclohexylmethy) adipate, 
dicyclopentadiene oxide or bis(2,3-epoxycyclopentyl) ether. 
When the melamine-type heat-curing agent and the epoxy-type heat-curing 
agent are used in combination as the heat-curing agent, the 
above-mentioned melamine-type heat-curing agents and the epoxy-type 
heat-curing agents may be used in suitable combinations. 
When a halation-preventing function is required for the planarizing 
material in the present invention, a halation-preventive agent may be 
further added to the planarizing material. Namely, the planarizing 
material having a halation-preventing function comprises the resin capable 
of having its practical temperature for a planarizing step set at a level 
lower than 200.degree. C., the heat-curing agent and the 
halation-preventive agent. Here, the halation-preventive agent to be 
incorporated, is not particularly restricted so long as it is a compound 
capable of absorbing light of the light source for exposure, and an 
appropriate halation-preventive agent may be selected for use depending 
upon the particular purpose. For example, compounds of benzophenone type, 
triazole type, salicylate type, cyanoacrylate type, hindered amine type, 
chalcone type, cinnamic acid type, azo type, stilbene type and stilbazole 
type, may be mentioned. Specifically, the benzophenone type may, for 
example, be 2-hydroxy-4-methoxybenzophenone, 
2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 
2-hydroxy-4-benzyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 
2-hydroxy-4-methoxybenzophenone-5-sulfonic acid or its salt, or 
2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-disulfonic acid or its 
salt. The triazole type may, for example, be 
2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 
2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 
2-(2'-hydroxy-3', 5'-di-t-butylphenyl)benzotriazole or 2-2'-hydroxy-3', 
5'-bis(e,e'-dimethylbenzyl)phenyl!-2H-benzotriazole. The salicylate type 
may, for example, be 2,4-di-t-butylphenyl-3', 
5'-di-t-butyl-4'-hydroxybenzoate, 4-t-butylphenyl salicylate, phenyl 
salicylate or 4-t-octylphenyl salicylate. The cyano acrylate type may, for 
example, be ethyl-2-cyano-3,3-diphenyl acrylate or 
2-ethylhexyl-2-cyano-3,3-diphenyl acrylate. The hindered amine type may, 
for example, a condensation product of 
N,N'-bis(3-aminopropyl)ethylenediamine with 
2,4-bisN-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino!-6-chloro-1,3,5 
-triazine, succinic acid-bis(2,2,6,6-tetramethyl-4-piperidinyl) ester or 
2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate 
bis(1,2,2,6,6-pentamethyl-4-piperidyl). The chalcone type may, for 
example, be 2'-hydroxychalcone. The cinnamic acid type may, for example, 
be an ester of trans-o-methoxycinnamic acid, an ester of m-methoxycinnamic 
acid, an ester of p-methoxycinnamic acid, or an ester of 
.alpha.-cyanocinnamic acid. The azo type may, for example, be 
p-(N,N-dimethylamino)azobenzene, 2,4-bis(N,N-dimethylamino)azobenzene or 
4,4'-bis(N,N-dimethylamino)azobenzene. The stilbene type may, for example, 
be 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene, 
1,4-bis(2-methylstyryl)benzene, p-(dimethylamino)stilbene, 
4-methoxy-4'-nitrostilbene or tetraphenylethylene. The stilbazole type 
may, for example, be 4-(3', 4'-dimethoxystyryl)pyridine, 2-(3', 
4'-dimethoxystyryl)pyridine, 4-(3', 4'-dimethoxystyryl)quinoline, 
4-(3'-methoxy-4'-ethoxystyryl)quinoline, 
2-(3'-methoxy-4'-ethoxystyryl)quinoline, 2-(3', 4'-dimethoxystyryl) 
thiazole, 2-(3'-methoxy-4'-ethoxystyryl) thiazole or 
2-(3'-methoxy-4'-ethoxystyryl) oxazole. 
When a halation-preventive agent is simply added to the planarizing 
material, an extra amount of the agent corresponding to the amount which 
will be evaporated and sublimed during the heating and fluidizing of the 
planarizing material, may additionally be added beforehand, or for the 
purpose of preventing such evaporation or sublimation, a certain 
adjustment may be applied to the heating process, for example, be 
prolonging the temperature raising time to a prescribed heating 
temperature. 
On the other hand, it is preferred to employ a specific compound having a 
functional group reactive for an addition reaction with at least one of 
the resin capable of having its practical temperature for a planarizing 
step set at a level lower than 200.degree. C., the heat-curing agent and 
the halation-preventive agent, as the halation-preventive agent, so that 
evaporation or sublimation of the halation-preventive agent during the 
heating and fluidizing of the planarizing material, can be prevented, and 
the object can adequately be attained by an addition of a small amount of 
the halation-preventive agent. 
When the halation-preventive agent is the one having a functional group 
reactive for an addition reaction with at least one of the resin, the 
heat-curing agent and the halation-preventive agent, it is preferred to 
employ an acrylic resin as the resin capable of having its practical 
temperature for a planarizing step set at a level lower than 200.degree. 
C., for a reason such that various properties such as transparency and 
heat durability of the cured coating film, which are important 
particularly in the field of the production of charge coupled devices and 
liquid crystal display devices, are excellent. Further, it is more 
preferred to employ an acrylic resin having structural units of the 
following formula (3) or (4) having a functional group which is reactive 
with the heat-curing agent for an effective crosslinking reaction and 
which is also reactive with the halation-preventive agent for an effective 
addition reaction: 
##STR3## 
wherein each of R.sub.4, R.sub.5 and R.sub.6 is hydrogen or a methyl 
group, and each of A.sub.4 and A.sub.5 is OB.sub.4 or NB.sub.5 B.sub.6, 
wherein each of B.sub.4, B.sub.5 and B.sub.6 is hydrogen, a C.sub.1-6 
alkyl, alkenyl or hydroxyalkyl group, a C.sub.2-12 epoxy group, a 
C.sub.6-12 aryl group or a C.sub.7-12 aralkyl group, and each of x, y and 
z is a positive number inclusive of 0 and they satisfy the following 
formulas: 
EQU 0.ltoreq.x/(x+y+z).ltoreq.1 
EQU 0.ltoreq.y/(x+y+z).ltoreq.1 
EQU 0.ltoreq.z/(x+y+z).ltoreq.1 
##STR4## 
wherein each of R.sub.7, R.sub.8 and R.sub.9 is hydrogen or a methyl 
group, each of A.sub.6 and A.sub.7 is OB.sub.7 or NBSB.sub.9, wherein each 
of B.sub.7, B.sub.8 and B.sub.9 is hydrogen, a C.sub.1-6 alkyl, alkenyl or 
hydroxyalkyl group, a C.sub.2-12 epoxy group, a C.sub.6-12 aryl group or a 
C.sub.7-12 aralkyl group, and each of x, y and z is a positive number 
inclusive of 0 and they satisfy the following formulas: 
EQU 0.ltoreq.x/(x+y+z).ltoreq.1 
EQU 0.ltoreq.y/(x+y+z).ltoreq.1 
EQU 0.ltoreq.z/(x+y+z).ltoreq.1 
The alkyl group for B.sub.4 to B.sub.9 in the above two formulas may, for 
example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl 
group, a n-butyl group, an isobutyl group, a t-butyl group, a n-amyl 
group, an isoamyl group, a n-hexyl group and a cyclohexyl group; the epoxy 
group may, for example, be a glycidyl epoxy group such as an ethylenoxide 
group or a propylenoxide group, or an alicyclic epoxy group such as a 
cyclohexenoxide group, a cyclopentenoxide group or a tricyclodecenoxide 
group; and the aryl group may, for example, be a phenyl group, a tolyl 
group, a xylyl group, an ethylphenyl group or a naphthyl group, and some 
hydrogen atoms on an aromatic ring in the aryl group may be substituted by 
e.g. a halogen atom such as chlorine or bromine, a nitro group or a cyano 
group. The aralkyl group may, for example, be a benzyl group or a phenetyl 
group, and some hydrogen atoms on an aromatic ring of the aralkyl group 
may be substituted by e.g. a halogen atom such as chlorine or bromine, a 
nitro group or a cyano group. 
The halation-preventive agent having a functional group which undergoes an 
addition reaction under heating, includes, for example, compounds of 
benzophenone type, salicylate type, cyano acrylate type, chalcone type, 
cinnamic acid type, azo type, stilbene type and stilbazole type. The 
functional group reactive for an addition reaction with at least one of 
the resins, etc., may, for example, be an alcoholic hydroxyl group, a 
phenolic hydroxyl group, an organic acid, an acid anhydride, a primary 
amine, a secondary amine, an epoxy group or an aldehyde group. As specific 
examples of such a halation-preventive agent, the benzophenone type may, 
for example, be 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 
2,4,6-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 
2,3,4,4'-tetrahydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 
2,3,3', 4,4'-pentahydroxybenzophenone, 2,3,3', 4,4', 
5'-hexahydroxybenzophenone or partially oxidized derivatives of these 
benzophenone compounds. The salicylate type may, for example, be 
4-hydroxynaphthyl salicylate. The cyano acrylate type may, for example, be 
ethyl-2-cyano-3,3-bis(4'-hydroxydiphenyl) acrylate. The chalcone type may, 
for example, be 2-hydroxychalcone, 4-hydroxychalcone or 
4'-hydroxychalcone. The cinnamic acid type may, for example, be 
o-chlorocinnamic acid, .alpha.-cyanocinnamic acid, p-aminocinnamic acid, 
3,4-dihydroxycinnamic acid or 3,4-dimethoxycinnamic acid. The azo type 
may, for example, be o-toluene-azo-o-toluidine, p-aminoazobenzene and 
2,4-diaminoazobenzene. The stilbene type may, for example, be 
4-amino-4'-(N,N-dimethylamino)stilbene or 4-amino-4'-methoxystilbene. The 
stibazole type may, for example, be 4-(4'-hydroxystyryl)pyridine, 
4-(3'-methoxy-4'-hydroxystyryl)pyridine, 
2-(3'-methoxy-4'-hydroxystyryl)pyridine, 
4-(3'-methoxy-4'-hydroxystyryl)quinoline, 2-(4'-formylstyryl)pyridine, 
4-(4'-formylstyryl)pyridine, 2-(4'-formylstyryl)quinoline, 
4-(4'-formylsiryl)quinoline, 2-(4'-carboxystyryl)quinoline, 
4-(4'-carboxystyryl)quinoline, 2-(4'-carboxystyryl)pyridine or 
4-(4'-carboxystyryl)pyridine. 
Among these compounds, benzophenone-type compounds are preferred, since 
they satisfy the requirements for excellent compatibility with the resin 
and excellent transparency of the cured coating film in a visible light 
region, which are important in the field of the production of charge 
coupled devices and liquid crystal display devices. When the resin capable 
of having its practical temperature for a planarizing step set at a level 
lower than 200.degree. C., is an acrylic resin comprising structural units 
of the formula (3) or (4), it is particularly preferred to employ a 
benzophenone-type halation-preventive agent comprising structural units of 
the following formula (5), which has a functional group capable of 
undergoing an addition reaction effectively under heating and which has a 
high absorption coefficient in an ultraviolet region and serves as a 
cocatalyst during the heat-curing operation: 
##STR5## 
wherein each of R.sub.10 to R.sub.18 is hydrogen or --OW, wherein W is 
hydrogen or a C.sub.1-5 alkyl group, provided that at least one of 
R.sub.1O to R.sub.18 is --OH. 
Further, a benzophenone-type halation-preventive agent comprising 
structural units of the following formula (7), which has --OH at the 2- 
and 2'-positions, is particularly preferred, since such an agent has a 
strong absorption in the vicinity of 365 nm in the ultraviolet region, 
which is particularly effective for preventing halation in the 
lithographic process using an i-line light source: 
##STR6## 
wherein each of R.sub.23 to R.sub.30 is hydrogen or --OW, wherein W is 
hydrogen or a C.sub.1-5 alkyl group, provided that at least one of 
R.sub.23 to R.sub.30 is --OH. 
When the resin capable of having its practical temperature for a 
planarizing step set at a level lower than 200.degree. C., is an acrylic 
resin, the --OH group present at the 2-position (or 2'-position) of the 
benzophenone-type compound, is essential to impart excellent light 
absorbing properties. Further, the --OH group present at a position other 
than the 2-position (or 2- and 2'-positions), is essential for the 
effective addition reaction with an acrylic resin comprising structural 
units of the formula (3) or (4), or with the heat-curing agent comprising 
structural units of the formula (2). 
In the present invention, a curing catalyst may further be incorporated to 
shorten the time or to change the temperature for the curing operation, so 
that the curing conditions may properly be selected depending upon the 
process for the production of the particular device. 
The curing catalyst to be used in the present invention is not particularly 
restricted so long as it does not impair the required functions, and it 
may, for example, be an aliphatic acid anhydride, an alicyclic acid 
anhydride, an aromatic acid anhydride, a halogenated acid anhydride, a 
polybasic carboxylic acid, a photocatalytically acid-generating agent, a 
thermally acid-generating agent, an amine compound or a polyamine 
compound. Specifically, the aliphatic acid anhydride may, for example, be 
polyadipic anhydride, polyazelaic anhydride, polysebasic anhydride or 
poly(ethyloctadecanoic) anhydride. The alicyclic anhydride may, for 
example, be methyltetrahydrophthalic anhydride, methylhexahydrophthalic 
anhydride, methylhimic anhydride, hexahydrophthalic anhydride, 
tetrahydrophthalic anhydride, a trialkyltetrahydrophthalic anhydride or 
methylcyclohexenedicarboxylic anhydride. The aromatic acid anhydride may, 
for example, be phthalic anhydride, trimellitic anhydride, pyromellitic 
anhydride, benzophenonetricarboxylic anhydride, 
benzophenonetetracarboxylic anhydride, ethylene glycol bistrimellitate or 
glycerol tristrimellitate. The halogenated acid anhydride may, for 
example, be chlorendic anhydride or tetrabromophthalic anhydride. The 
polybasic carboxylic acid may, for example, an alicyclic acid anhydride, 
an aromatic acid anhydride, a hydrolyzate of halogenated anhydride, 
succinic acid, glutaric acid, adipic acid, butanetetracarboxylic acid, 
maleic acid, malonic acid, itaconic acid, 1,2,4-cyclohexanetricarboxylic 
acid, cyclopentanetetracarboxylic acid or 
1,4,5,8-naphthalenetetracarboxylic acid. The amine compound and the 
polyamine compound may, for example, be an aliphatic amine (primary, 
secondary or tertiary), an aromatic amine (primary, secondary or 
tertiary), various modified amine compounds, an imidazole compound, an 
aliphatic polyamine or an aromatic polyamine. With respect to specific 
examples of such an amine compound and a polyamine compound, the aliphatic 
amine may, for example, be ethylenediamine, 1,3-diaminopropane, 
1,4-diaminobutane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, 
piperidine, pyrrolidine, triethylenediamine, 
trimethylhexamethylenediamine, dimethylcyclohexylamine, 
tetramethylguanidine, triethanolamine, N,N'-dimethylpiperadine, 
dicyanamide or its derivative. The aromatic amine may, for example, be 
metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, 
diaminodiethyldiphenylmethane, benzyldimethylamine, 
dimethylamino-p-cresol, 2-(dimethylaminedimethyl)phenol, 
2,4,6-tris(dimethylaminomethyl)phenol, pyridine, picoline, DBU 
(1,8-diazabicyclo(5,4,0)undecene-1) or a tri-2-ethylhexyl acid salt of 
2,4,6-tris(dimethylaminomethyl)phenol. The modified amine compound may, 
for example, be an amine adduct such as a polyamine-epoxy resin adduct or 
a polyamine-ethylene oxide adduct, a Lewis acid-amine complex such as a 
boron-trifluoride-amine complex, cyanoethylated polyamine, kerimine, 
dicyanamide or its derivative, or an organic acid hydrazide. The imidazole 
compound may, for example, be 2-methylimidazole, 
2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 
2-phenylimidazole, 1-benzyl-2-methylimidazole, 
1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 
1-cyanoethyl-2-undecylimidazole, 
1-cyanoethyl-2-undecylimidazolium-trimellitate, 
2-methylimidazolium-isocyanulate, 2-phenylimidazolium-isocyanulate, 
2,4-diamino-6-methylimidazolyl-(1)!-ethyl-S-triazine, 
2,4-diamino-6-2-ethylimidazolyl-(1)!-ethyl-S-triazine, 
2,4-diamino-6-2-undecylimidazolyl-(1)!-ethyl-S-triazine, 
2-phenyl-4,5-dihydroxymethylimidazole, 
2-phenyl-4-methyl-5-hydroxymethylimidazole or 
1-cyanoethyl-2-phenyl-4,5-di(cyanoethoxymethyl)imidazole. The aliphatic 
polyamine may, for example, be diethylenetriamine, iminobispropylamine, 
bis(hexamethylene)triamine, triethyltetramine, tetraethylenepentamine, 
pentaethylenehexamine, dimethylaminopropylamine, diethylaminopropylamine, 
N-aminoethylpiperadine, menthenediamine, isofluorodiamine, 
bis(4-amino-3-methylcyclohexyl)methane or diaminodicyclohexylamine. The 
aromatic polyamine may, for example, be m-xylenediamine, xylylenediamine, 
a xylylenediamine derivative or a xylylenediamine trimer. Except for some 
special curing catalyst, when curing catalysts mentioned here will be 
employed, they may preferably be stored under a cool temperature condition 
to maintain the storage stability. Further, it is preferred to employ a 
curing catalyst which provides a catalytic activity when decomposed under 
heating and which has a functional group reactive for an addition reaction 
with at least one of the resin capable of having its practical temperature 
for a planarizing step set at a level lower than 200.degree. C., the 
heat-curing agent, the halation-preventive agent and the curing catalyst, 
as the curing catalyst, since it is thereby possible to prevent the 
evaporation or sublimation of the catalyst which is likely to take place 
during the heating and fluidizing or to prevent a deterioration of the 
commercial product due to migration which takes place by a heat history 
after assembled in the commercial product. 
The functional group reactive for an addition reaction with at least one of 
the resin, etc., may, for example, be an alcoholic hydroxyl group, a 
phenoic hydroxyl group, an organic acid, an acid anhydride, a primary 
amine, a secondary amine, an epoxy group or an aldehyde group. 
Here, as the curing catalyst, it is particularly preferred to use an 
aromatic amine of the following formula (6) or a COOH group-containing 
acid anhydride alone or in combination, which has a good balance of the 
planarization by heating and fluidizing and the activity of the curing 
reaction and is able to prevent evaporation, sublimation and migration and 
which is able to improve the storage stability of the planarizing material 
in a solution state, whereby no substantial deterioration of the material 
will be brought about even when left to stand at room temperature for a 
long period of time and simple and mild process conditions can be set: 
##STR7## 
wherein each of R.sub.19 to R.sub.22 is hydrogen or a C.sub.1-5 alkyl 
group, provided that at least one of R.sub.19 to R.sub.22 is a hydrogen 
atom, and D is a methylene group, a carbonyl group, a sulfide group, a 
sulfoxide group or a sulfone group. 
Here, the aromatic amine of the formula (6) may, for example, be 
diaminodiphenylmethane, diaminodiphenylsutfone or 
diaminodiethyldiphenylmethane. The COOH group-containing acid anhydride 
may, for example, be trimellitic anhydride or benzophenonetricarboxylic 
anhydride. When the planarization by heating and fluidizing and the curing 
reaction are conducted in the same process step employing the planarizing 
material of the present invention, the balance of the activity of the 
curing reaction is very important, and for this purpose, selection of the 
curing catalyst is particularly important. Namely, it is necessary to 
select a curing catalyst system so that it has a characteristic such that 
no curing reaction will take place during the heating and fluidizing of 
the resin, and the curing reaction readily takes place after the heating 
and fluidizing, and it has a good storage stability. From the foregoing 
viewpoint, it is preferred to employ a curing catalyst of a 
photocatalytically acid-generating agent type or a thermally 
acid-generating agent type which exhibits a catalytic activity after 
decomposition by heating or irradiation with light. As such a 
photocatalytically acid-generating agent or thermally acid-generating 
agent, various onium salt compounds such as an aromatic diazonium salt, a 
diaryliodonium salt, a triarylsulfonium salt and a triarylselenium salt, a 
sulfonic acid ester, and a halogen compound, may, for example, be 
mentioned. Specifically, the aromatic diazonium salt may, for example, be 
chlorobenzenediazonium hexafluorophosphate, dimethylaminobenzenediazonium 
hexafluoroantimonate, naphthyldiazonium hexafluorophosphate or 
dimethylaminonaphthyldiazonium tetrafluoroborate. The diaryliodonium salt 
may, for example, be diphenyliodoniumtetrafluoroborate, diphenyliodonium 
hexafluoroantimonate, diphenyliodonium hexafluorophosphate, 
diphenyliodonium triflate, 4,4'-di-t-butyl-diphenyliodonium triflate, 
4,4'-di-t-butyl-diphenyliodonium tetrafluoroborate or 
4,4'-di-t-butyl-diphenyliodonium hexafluorophosphate. The triarylsulfonium 
salt may, for example, be triphenylsulfonium tetrafluoroborate, 
triphenylsulfonium hexafluorophosphate, triphenylsulfonium 
hexafluoroantimonate, tri(p-chlorophenyl)sulfonium tetrafluoroborate, 
tri(p-chlorophenyl)sulfonium hexafluorophosphate, 
tri(p-chlorophenyl)sulfonium hexafluoroantimonate or 
4-t-butyltriphenylsulfonium hexafluorophosphate. The triarylselenium salt 
may, for example, be triarylselenium tetrafluoroborate, 
triarylseleniumhexafluorophosphate, triarylselenium hexafluoroantimonate, 
di(chlorophenyl)phenylselenium tetrafluoroborate, 
di(chlorophenyl)phenylselenium hexafluorophosphate or 
di(chlorophenyl)phenylselenium hexafluoroantimonate. The sulfonic acid 
ester may, for example, be benzoin tosylate, 
p-nitrobenzyl-9,10-ethoxyanthracene-2-sulfonate, 2-nitrobenzyltosylate, 
2,6-dinitrobenzyltosylate or 2,4-dinitrobenzyltosylate. The halogen 
compound may, for example, be 2-chloro-2-phenylacetophenone, 2,2', 
4'-trichloroacetophenone, 2,4,6-tris(trichloromethyl)-s-triazine, 
2-(p-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 
2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 
2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 
2-(4'-methoxy-1-naphthyl)-4,6-bis(trichloromethyl)-s-triazine, 
bis-2-(4-chlorophenyl)-1,1,1-trichloroethane, 
bis-1-(4-chlorophenyl)-2,2,2-trichloroethanol or 
bis-2(4-methoxyphenyl)-1,1,1-trichloroethane. 
Among these curing catalysts, onium salt type compounds are particularly 
preferred, since the balance of planarization by heating and fluidizing 
and the activities for the curing reaction, is good, and they can readily 
be decomposed by various light sources for exposure to exhibit the 
activities. 
Further, from the viewpoint of a particularly important balance of 
heat-fluidity and heat-curing to obtain a higher level of flatness at a 
site where stricter flatness is required or at a site having a stepped 
configuration which is more hardly planarized, more preferred are the 
following specific sulfonium salts which decompose at relatively high 
temperatures and then exhibit catalytic activities. Such sulfonium salts 
are excellent also in the storage stability. They are, for example, 
benzyl-p-hydroxyphenylmethylsulfonium hexafluorophosphate, 
p-hydroxyphenyldimethylsulfonium hexafluoroantimonate, 
p-acetoxyphenyldimethylsulfonium hexafluoroantimonate, benzyl 
p-hydroxymethylsulfonium hexafluoroantimonate, and a monophenylsulfonium 
salt type or benzylphenylsulfonium salt type such as a compound of the 
following formula (8): 
##STR8## 
wherein Z is a phenyl group. 
The planarizing material of the present invention is composed of the resin 
capable of having its practical temperature for a planarizing step set at 
a level lower than 200.degree. C., the heat-curing agent, etc. and has 
characteristics in the respective materials and their combination. Namely, 
by the combination of the resin capable of having its practical 
temperature for a planarizing step set at a level lower than 200.degree. 
C. and the heat-curing agent, as mentioned above, particularly by the 
combination of an acrylic resin and a melamine-type heat-curing agent, an 
acrylic resin and an epoxy-type heat-curing agent, or an acrylic resin, a 
melamine-type heat-curing agent and an epoxy-type heat-curing agent, it is 
possible to let the planarization by heating and fluidizing and the curing 
reaction proceed in the same process step. Therefore, no special curing 
step is required, which is very advantageous from the viewpoint of the 
process. Further, the planarizing material of the present invention has 
excellent transparency for a visible light of at least 400 nm required in 
the field of the production of charge coupled devices and liquid crystal 
display devices and is capable of presenting a system wherein the 
transparency undergoes no change with time even when left to stand under a 
high temperature condition over a long period of time. 
Further, when the planarizing material is required to have a 
halation-preventing function, a halation-preventive agent having a 
functional group which will be taken into the system by an addition 
reaction, is combined with a resin, whereby a halation-preventing function 
is effectively obtained without evaporation or sublimation even under a 
high temperature condition during the planarizing/curing step. Further, if 
a curing catalyst which can be taken into the system by an addition 
reaction, is used in combination, not only the evaporation and sublimation 
but also migration can be prevented, and if the above halation-preventive 
agent is contained, this agent will serve as a cocatalyst, whereby the 
amount of the curing catalyst can be reduced, such being advantageous. 
Further, by adjusting the amounts of the halation-preventive agent and the 
curing catalyst, the dry etching durability (such as oxygen gas 
durability) and the refractive index can be controlled, and the heat 
durability (such as the decomposition property at 250.degree. C.) can be 
increased. It has been found that the dry etching durability can also be 
controlled by the copolymerization of the acrylic monomer with an 
aromatic-containing monomer. However, it can also be controlled by a 
combination of a polymer of an acrylic monomer (among the polymers of the 
formulas (1), (3) and (5), those containing no aromatic ring) with the 
compound of the formula (6). This is epoch-making in that the dry etching 
durability can be controlled by an inexpensive method. Further, light 
(incident light, transmitted light) is employed in a solid-state image 
pick-up device or a liquid crystal display device, and it is also 
significant from the industrial point of view that the refractive index 
can be controlled by a simple method. 
In the planarizing material of the present invention, the compositional 
ratios of the resin capable of having its practical temperature for a 
planarizing step set at a level lower than 200.degree. C., the heat-curing 
agent and the halation-preventive agent can be changed variously within 
the ranges where the desired properties can be maintained. However, the 
heat-curing agent is used usually within a range of from 1 to 50% by 
weight, preferably from 5 to 30% by weight, relative to the resin and the 
heat-curing agent, or relative to the resin, the heat-curing agent and the 
halation-preventive agent. Within this range, good and constant properties 
can be obtained with respect to the adhesiveness, the transparency, the 
heat durability and the solvent resistance after curing. The 
halation-preventive agent is used usually within a range of from 1 to 40% 
by weight, preferably from 1 to 20% by weight, relative to the resin, the 
heat-curing agent and the halation-preventive agent. Within this range, an 
effective halation-preventing function can be imparted while maintaining 
transparency to a visual light of at least 400 nm required particularly in 
the field for the production of charge coupled devices and liquid crystal 
display devices. The amount of the curing catalyst to be used here, is not 
particularly limited so long as a catalyst system having a good balance of 
heat-fluidity and heat-curing is employed. The reason is that the 
catalytic function can readily be satisfied if the catalyst is 
incorporated in an amount to satisfy the time required for the step of 
preparing a commercial product. 
Further, if necessary, for the purpose of lowering the softening point of 
the resin and improving the fluidity under heating, various additives 
including a common plasticizer such as a phthalic acid ester (dimethyl 
phthalate or dibutyl phthalate), an aromatic carboxylic acid ester (such 
as trioctyl trimellitate or diethylene glycol dibenzoate), an aliphatic 
dibasic acid ester (such as dioctyl succinate or dioctyl adipate), an 
aliphatic ester derivative (such as butyl oleate or methyl 
acetylricinoleate) or phosphoric acid ester (tricresil or trioctyl), a 
reactive plasticizer such as diallyl phthalate or a methacrylic acid 
diester, an acrylic monomer, and a low molecular weight material such as 
an oligomer, may be incorporated to the planarizing material. Further, in 
order to improve the flexibility of the cured coating film, various 
flexibility-imparting agents such as epoxide, polyol, polythiol and 
silicone compounds, may be incorporated. 
The planarizing material of the present invention is usually in the form of 
a solution having the resin capable of having its practical temperature 
for a planarizing step set at a level lower than 200.degree. C. and the 
heat-curing agent dissolved in a suitable solvent so that the resin and 
the heat-curing agent would be from 10 to 40 parts by weight. Here, the 
solvent may, for example, be ethylene glycol monoalkyl ethers and acetates 
thereof, propylene glycol monoalkyl ethers and acetates thereof, 
diethylene glycol mono- or di-alkyl ethers, ketones such as methyl ethyl 
ketone, methyl isobutyl ketone and cyclohexanone, acetic acid esters such 
as ethyl acetate and butyl acetate, aromatic hydrocarbons such as toluene 
and xylene, ethyl lactate, diacetone alcohol, dimethylacetamide, 
dimethylformamide, and N-methylpyrrolidone. These solvents may be used 
alone or in combination as a mixture of two or more of them. Further, in 
order to improve the coating properties, a surfactant such as a nonionic 
surfactant, a fluorine-type surfactant or a silicon-type surfactant, may 
be incorporated, as the case requires. Further, other compatible additives 
may be incorporated, if necessary. 
As described in the foregoing, by coating the planarizing material of the 
present invention on a substrate having surface irregularities, not only 
planarization by heating and fluidizing but also heat-curing can be 
carried out in the same process step, whereby a cumbersome step is not 
required. 
Now, a planarizing method by means of the planarizing material of the 
present invention will be described. 
The planarizing material of the present invention is usually used in the 
form of a solution. Firstly, predetermined amounts of the resin capable of 
having its practical temperature for a planarizing step set at a level 
lower than 200.degree. C. and the heat-curing agent, as well as the curing 
catalyst and/or the halation-preventive agent, if necessary, are dissolved 
in the above-mentioned organic solvent, followed by filtration with a 
filter of 0.2 .mu.m to obtain a solution. Then, the solution of the 
planarizing material is spin-coated on a substrate having a stepped 
portion and then heated and fluidized on a hot plate or in an oven to 
conduct planarization and heat-curing simultaneously. The temperature at 
that time is not particularly limited so long as it is within a range of 
from 120.degree. to 250.degree. C. The temperature is preferably from 130 
.degree. to 200.degree. C. Here, a two step baking method may be employed, 
for example, by conducting planarization by the first baking, followed by 
heat-curing either for a long curing period at the same temperature or for 
a short period of time at a higher temperature. Further, when spin-coating 
is not available, a roll coater method or a printing method may be 
employed for coating without any problem. After planarization with the 
material of the present invention, various layers (such as color filter 
layers) may be formed by patterning by a lithography method on the 
planarized layer from the necessity of the process, and any stepped 
portion resulting from the patterning may be likewise planarized with the 
same planarizing material. 
In this planarizing method, the temperature, the time, etc. are not 
particularly limited and may be suitably adjusted depending upon the 
particular application. 
Now, the present invention will be described in further detail with 
reference to Examples. However, it should be understood that the present 
invention is by no means restricted by such specific Examples. 
EXAMPLE 1 
Into a 1 l four-necked flask, 8.0 g of acrylic acid, 13.5 g of n-butyl 
acrylate, 28.5 g of methyl methacrylate, 10.0 g of 
2,2'-azobisisobutylonitrile (AIBN), 5.0 g of n-dodecylmercaptan and 500 ml 
of dioxane were charged, dissolved and stirred. Then, stirring was 
continued under a nitrogen stream at 70.degree. C. for 6 hours. The 
reaction solution was put into n-hexane to precipitate the resin. 
Purification with tetrahydrofuran/n-hexane was repeated, followed by 
vacuum drying at 40.degree. C. to obtain a resin powder. The obtained 
amount was 43.0 g. The weight average molecular weight as measured by GPC 
was 15,000 as calculated as polystyrene; the glass transition temperature 
(Tg) was 53.degree. C.; and the acid value calculated after titration by 
means of a potentiometer was 60. 25 g of a methacrylic acid/n-butyl 
acrylate/methyl methacrylate copolymer thus obtained, 4.5 g of a 
melamine-type heat-curing agent (hexamethoxymethylolmelamine, CYMEL 
(trademark) 303, manufactured by Mitsui Cyanamid) and 75 g of diethylene 
glycol dimethyl ether were mixed and dissolved, followed by filtration 
with a 0.2 .mu.m filter to obtain a planarizing material solution. 
A silicon substrate having a silicon dioxide film formed in a thickness of 
1 .mu.m, was subjected to photolithography and reactive ion etching to 
form surface irregularities, and the planarizing material solution was 
spin-coated on this substrate in a thickness of 2.0 .mu.m, followed by 
baking at 150.degree. C for 10 minutes on a hot plate to form a planarized 
film. 
The flatness of this planarized film was inspected by means of a 
contact-type step measuring apparatus (TALY-STEP, trademark), manufactured 
by Rank Taylor Hobson Company), whereby no substantial irregularities were 
observed on the planarized film, and planarization was found to be 
completely done. Further, after the planarized film was formed, a heating 
test on a hot plate was conducted at 200.degree. C. for 5 minutes, whereby 
no decrease of the film thickness due to flowing of the planarized layer 
was observed, and no change of the film surface was observed. With respect 
to the solvent resistance, no surface roughening was observed when 
immersed in a solvent such as water, isopropyl alcohol, trichloroethane or 
xylene. Further, the transparency of the planarized layer in a visible 
light region was excellent, and, for example, it was 98.0% (thickness: 1 
.mu.m) at 400 nm. No change in this transparency was observed even after 
the heat treatment on the hot plate at 200.degree. C. for one hour. 
EXAMPLE 2 
Into a 1 l four-necked flask, 10.0 g of methacrylic acid, 15.0 g of n-butyl 
acrylate, 25.0 g of methyl methacrylate, 10.0 g of 
2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 5.0 g of 
n-dodecylmercaptan and 500 ml of dioxane were charged, dissolved and 
stirred. Then, stirring was continued under a nitrogen stream at 
70.degree. C. for 6 hours. The reaction solution was put into n-hexane to 
precipitate the resin. Purification was repeated with 
tetrahydrofuran/n-hexane, and then vacuum drying was conducted at 
40.degree. C. to obtain a resin powder. The obtained amount was 40.0 g. 
The weight average molecular weight as measured by GPC was 4,000 as 
calculated as polystyrene; the glass transition temperature (Tg) was 
65.degree. C.; and the acid value calculated after titration by means of a 
potentiometer was 130. 25 g of a methacrylic acid/n-butyl acrylate/methyl 
methacrylate copolymer thus obtained, 4.5 g of a melamine-type heat-curing 
agent (CYMEL (trademark) 303, manufactured by Mitsui Cyanamid) and 75 g of 
diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was employed. Further, in the same 
manner as in Example 1, inspection of the surface was conducted, whereby 
no irregularities on the planarized film was observed, and planarization 
was found to be completely done. With respect to the solvent resistance, 
no surface roughening was observed when immersed in a solvent such as 
water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 3 
Into a 1 l four-necked flask, 10.0 g of hydroxyethyl methacrylate, 40.0 g 
of isobutyl methacrylate, 10.0 g of 2,2'-azobisisobutylnitrile (AIBN), 5.0 
g of n-dodecylmercaptan and 500 ml of dioxane were charged, dissolved and 
stirred. Then, stirring was continued under a nitrogen stream at 
70.degree. C. for 6 hours. The reaction solution was put into n-hexane to 
precipitate the resin. Purification was repeated with 
tetrahydrofuran/n-hexane, and then vacuum drying was conducted at 
40.degree. C. to obtain a resin powder. The obtained amount was 40.0 g. 
The weight average molecular weight as measured by GPC was 16,000 as 
calculated as polystyrene; the glass transition temperature (Tg) was 
59.degree. C.; and the acid value calculated after titration by means of a 
potentiometer was 110. 25 g of a hydroxyethyl methacrylate/isobutyl 
methacrylate copolymer thus obtained, 4.4 g of a melamine-type heat-curing 
agent (CYMEL (trademark) 303, manufactured by Mitsui Cyanamid) and 83 g of 
ethyl lactate were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 4 
25 g of an acrylic acid/n-butyl acrylate/methyl methacrylate copolymer 
(weight average molecular weight: 1,000 as measured by GPC and as 
calculated as polystyrene, AW-36, manufactured by Seiko Kagaku Kogyo), 4.4 
g of a melamine-type heat-curing agent (CYMEL (trademark) 303, 
manufactured by Mitsui Cyanamid) and 83 g of ethyl lactate were mixed and 
dissolved, followed by filtration with a 0.2 .mu.m filter to obtain a 
planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 5 
Into a 1 l four-necked flask, 25.0 g of glycidyl methacrylate, 25.0 g of 
methyl methacrylate, 10.0 g of 
2,2'-azobis(4-methoxy-2,4-dimethylavleronitrile), 5.0 g of 
n-dodecylmercaptan and 500 ml of dioxane were charged, dissolved and 
stirred. Then, stirring was continued under a nitrogen stream at 
70.degree. C. for 4 hours. The reaction solution was put into methanol to 
precipitate the resin. Purification with tetrahydrofuran/methanol was 
repeated, and then vacuum drying was conducted at 40.degree. C. to obtain 
a resin powder. The obtained amount was 40.0 g. The weight average 
molecular weight as measured by GPC was 16,000 as calculated as 
polystyrene; the glass transition temperature (Tg) was 63.degree. C.; and 
the epoxy equivalent was 210. 25 g of a glycidyl methacrylate/methyl 
methacrylate copolymer thus obtained, 6.5 g of an epoxy-type heat-curing 
agent (a polyfunctional glycidyl ether, EX-611, manufactured by Nagase 
Chemicals Ltd.), 1.6 g of a curing catalyst (a sulfonium salt type 
thermally acid-generating agent), SI-190, manufactured by Shanshin 
Chemical Industry Co., Ltd.) and 77 g of diethylene glycol dimethyl ether 
were mixed and dissolved, followed by filtration with a 0.2 .mu.m filter 
to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface toughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 99.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 6 
Into a 1 l four-necked flask, 25.0 g of glycidyl methacrylate, 25.0 g of 
n-butyl methacrylate, 10.0 g of 
2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 5.0 g of 
n-dodecylmercaptan and 500 ml of dioxane were charged, dissolved and 
stirred. Then, stirring was continued under a nitrogen stream at 
70.degree. C. for 4 hours. The reaction solution was put into methanol to 
precipitate the resin. Purification was repeated with 
tetrahydrofuran/methanol, and then vacuum drying was conducted at 
40.degree. C. to obtain a resin powder. The obtained amount was 38.0 g. 
The weight average molecular weight as measured by GPC was 14,000 as 
calculated as polystyrene; the glass transition temperature (Tg) was 
33.degree. C.; and the epoxy equivalent was 205. 25 g of a glycidyl 
methacrylate/n-butyl methacrylate copolymer thus obtained, 6.5 g of an 
epoxy-type heat-curing agent (EX-611, manufactured by Nagase Chemicals 
Ltd.), 1.6 g of a curing catalyst (SI-190, manufactured by Shanshin 
Chemical Industry Co., Ltd.) and 77 g of diethylene glycol dimethyl ether 
were mixed and dissolved, followed by filtration with a 0.2 .mu.m filter 
to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 99.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 7 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 5.8 g of an epoxy-type heat-curing agent 
(a polyfunctional alicyclic epoxy, Celloxide 2021P, manufactured by Daisel 
Kagaku Kogyo), 1.5 g of a curing catalyst (SI-190, manufactured by 
Shanshin Chemical Industry Co., Ltd.) and 75.5 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 99.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 8 
Into a 1 l four-necked flask, 50.0 g of glycidyl methacrylate, 10.0 g of 
2,2'-azobisisobutylnitrile (AIBN), 5.0 g of n-dodecylmercaptan and 500 ml 
of dioxane were charged, dissolved and stirred. Then, stirring was 
continued under a nitrogen stream at 70.degree. C. for 4 hours. The 
reaction solution was put into methanol to precipitate the resin. 
Purification was repeated with tetrahydrofuran/methanol, and then vacuum 
drying was conducted at 40.degree. C. to obtain a resin powder. The 
obtained amount was 40.5 g. The weight average molecular weight as 
measured by GPC was 18,000 as calculated as polystyrene; the glass 
transition temperature (Tg) was 40.degree. C.; and the the epoxy 
equivalent was 155. 25 g of a glycidyl methacrylate polymer thus obtained, 
6.5 g of an epoxy-type heat-curing agent (EX-611, manufactured by Nagase 
Chemicals Ltd.), 1.6 g of a curing catalyst (SI-190, manufactured by 
Shanshin Chemical Industry Co., Ltd.) and 65 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.7% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 9 
25 g of a glycidyl methacrylate polymer (weight average molecular weight: 
11300 as measured by GPC and as calculated as polystyrene, epoxy 
equivalent: 168, Marp Roof U-100, manufactured by Nippon Oil and Fats Co., 
Ltd.), 6.5 g of an epoxy-type heat-curing agent (EX-611, manufactured by 
Nagase Chemicals Ltd.), 1.6 g of a curing catalyst (SI-190, manufactured 
by Shanshin Chemical Industry Co., Ltd.) and 65 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 10 
25 g of a methacrylic acid/n-butyl acrylate/methyl methacrylate copolymer 
obtained in the same manner as in Example 1, 2.0 g of a melamine-type 
heat-curing agent (CYMEL (trademark) 303, manufactured by Mitsui 
Cyanamid), 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 0.7 g of a curing catalyst (SI-190, 
manufactured by Shanshin Chemical Industry Co., Ltd.) and 72 g of 
diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 99.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 11 
25 g of a methacrylic acid/n-butyl acrylate/methyl methacrylate copolymer 
obtained in the same manner as in Example 1, 2.0 g of a melamine-type 
heat-curing agent (CYMEL (trademark) 303, manufactured by Mitsui 
Cyanamid), 3.0 g of an epoxy-type heat-curing agent (Celloxide 2021P, 
manufactured by Daisel Chemical Industries), 0.7 g of a curing catalyst 
(SI-190, manufactured by Shanshin Chemical Industry Co., Ltd.) and 72 g of 
diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 12 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 2.0 g of a curing 
catalyst (3,3'-diaminodiphenylsulfone) and 72 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
Further, for the study of storage stability, the change in viscosity at 
room temperature was examined, whereby no substantial increase in 
viscosity was observed even after being left at room temperature for 30 
days, whereby excellent storage stability was confirmed. 
EXAMPLE 13 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 2.0 g of a melamine-type heat-curing 
agent (CYMEL (trademark) 303, manufactured by Mitsui Cyanamid), 3.0 g of 
an epoxy-type heat-curing agent (EX-611, manufactured by Nagase Chemicals 
Ltd.), 2.0 g of a curing catalyst (3,3'-diaminodiphenylsulfone) and 72 g 
of diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 14 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 2.0 g of a melamine-type heat-curing 
agent (CYMEL (trademark) 303, manufactured by Mitsui Cyanamid), 3.0 g of 
an epoxy-type heat-curing agent (EX-611, manufactured by Nagase Chemicals 
Ltd.), 0.7 g of a curing catalyst (SI-190, manufactured by Shanshin 
Chemical Industry Co., Ltd.) and 72 g of diethylene glycol dimethyl ether 
were mixed and dissolved, followed by filtration with a 0.2 .mu.m filter 
to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 15 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 2.0 g of a melamine-type heat-curing 
agent (CYMEL (trademark) 303, manufactured by Mitsui Cyanamid), 3.0 g of 
an epoxy-type heat-curing agent (Celloxide 2021P, manufactured by Daisel 
Chemical Industries), 0.7 g of a curing catalyst (SI-190, manufactured by 
Shanshin Chemical Industry Co., Ltd.) and 72 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 16 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 2.0 g of a melamine-type heat-curing 
agent (CYMEL (trademark) 303, manufactured by Mitsui Cyanamid), 3.0 g of 
an epoxy-type heat-curing agent (Celloxide 2021P, manufactured by Daisel 
Chemical Industries) and 72 g of diethylene glycol dimethyl ether were 
mixed and dissolved, followed by filtration with a 0.2 .mu.m filter to 
obtain a planarizing material solution. 
On a substrate having a stepped portion obtained in the same manner as in 
Example 1, this planarizing material solution was spin-coated in a 
thickness of 2.0 .mu.m and baked at 160.degree. C. for 30 minutes on a hot 
plate to form a planarized film. 
The flatness of this planarized film was inspected by means of a 
contact-type step measuring apparatus (TALY-STEP (trademark), manufactured 
by Rank Taylor Hobson Company), whereby no substantial irregularities were 
observed on the planarized film, and planarization was found to be 
completely done. With respect to the solvent resistance, no surface 
roughening was observed when immersed in a solvent such as water, 
isopropyl alcohol, trichloroethane or xylene. Further, the transparency of 
the planarized layer in a visible light region was excellent, and, for 
example, it was 98.0% (thickness: 1 .mu.m) at 400 nm. No change in this 
transparency was observed even after the heat treatment at 200.degree. C. 
for one hour. 
EXAMPLE 17 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 0.15 g of a curing 
catalyst (SI-190, manufactured by Shanshin Chemical Industry Co., Ltd.), 
1.5 g of a halation-preventive agent (2,2', 4,4'-tetrahydroxybenzophenone) 
and 65 g of diethylene glycol dimethyl ether were mixed and dissolved, 
followed by filtration with a 0.2 .mu.m filter to obtain a planarizing 
material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 96.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
Further, as shown in FIG. 1, a sufficient absorption was observed in the 
i-line region, and no substantial change in the spectral characteristics 
was observed even after the heat treatment for one hour. 
On the other hand, FIG. 2 shows spectral characteristics in a case where 
the operation was conducted in the same manner except that 
2-hydroxy-4-methoxybenzophenone was used instead of 2,2', 
4,4'-tetrahydroxybenzophenone. As a result, with 
2-hydroxy-4-methoxybenzophenone, sublimation and dissipation took place in 
a short period of time by the heat treatment, and it was impossible to 
maintain satisfactory spectral characteristics, since it did not have a 
functional group effective for an addition reaction, although a sufficient 
absorption was observed in the i-line region. Thus, a halation-preventive 
agent having no functional group effective for an addition reaction can be 
used only for an application where the heat treatment is conducted at a 
relatively low temperature. 
Further, evaluation of spectral characteristics was conducted with respect 
to a planarizing material wherein 2,2', 4,4'-tetrahydroxybenzophenone was 
used as the halation-preventive agent. FIG. 3 shows the change of the 
transmittance with the curing time. 
Further, the storage stability was studied in the same manner as in Example 
12, whereby no substantial increase of the viscosity was observed even 
after being left at room temperature for 30 days, whereby excellent 
storage stability was confirmed. 
EXAMPLE 17 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 0.15 g of a curing 
catalyst (SI-190, manufactured by Shahshin Chemical industry Co., Ltd.), 
1.5 g of a halation-preventive agent (2,2', 4,4'-tetrahydroxybenzophenone) 
and 65 g of diethylene glycol dimethyl ether were mixed and dissolved, 
followed by filtration with a 0.2 .mu.m filter to obtain a planarizing 
material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
.transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 96.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 18 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g of a curing 
catalyst (3,3'-diaminodiphenylsulfone), 1.5 g of a halation-preventive 
agent (2,2', 4,4'-tetrahydroxybenzophenone) and 65 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
Further, an adequate adsorption was observed in the i-line region, and no 
substantial change in the spectral characteristics was observed even after 
the heat treatment for one hour. 
Further, in the same manner as in Example 12, the storage stability was 
studied, whereby no substantial increase in viscosity was observed after 
being left at room temperature for 30 days, whereby excellent storage 
stability was confirmed. 
EXAMPLES 19 AND 20 
Evaluation of the spectral characteristics was conducted in the same manner 
as in Example 17 using the same planarizing material except that as the 
halation-preventive agent, 2,2', 3,4,4'-pentahydroxybenzophenone (Example 
19) and 2,3,3', 4,4', 5'-hexahydroxybenzophenone (Example 20) were used. 
FIG. 3 shows the changes of the transmittance of the planarizing materials 
of Examples 19 and 20 with the curing time. 
EXAMPLE 21 
A planarizing material solution prepared in the same manner as in Example 
12 was spin-coated on a silicon substrate and then baked at 150.degree. C. 
for 10 minutes on a hot plate to form a planarized film having a thickness 
of 2.0 .mu.m. The dry etching durability of this planarized film was 
evaluated by means of a dry etching apparatus (CSE-1110 (trademark), 
manufactured by ULVAC corp.). The results of the evaluation are shown in 
FIG. 4. 
EXAMPLE 22 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 5.0 g of a curing 
catalyst (3,3'-diaminodiphenylsulfone) and 72 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
On a silicon substrate, this planarizing material solution was spin-coated 
and then baked at 150.degree. C. for 10 minutes on a hot plate to form a 
planarized film having a thickness of 2.0 .mu.m. The dry etching 
durability of this planarized film was evaluated by means of a dry etching 
apparatus (CSE-1110 (trademark), manufactured by ULVAC corp.). The results 
of the evaluation and the results of a comparative test conducted by using 
a planarizing material solution prepared in the same manner as in Example 
6, are shown in FIG. 4. 
From the evaluation results, the dry etching durability imparted by the 
addition of the curing catalyst (3,3'-diaminodiphenylsulfone) was 
confirmed. 
EXAMPLE 23 
A planarizing material solution prepared in the same manner as in Example 
12 was spin-coated on a silicon substrate and then baked at 150.degree. C. 
for 10 minutes on a hot plate to form a planarized film having a thickness 
of 2.0 .mu.m. This planarized film was heated on a hot plate of 
250.degree. C., whereby shrinkage of the film was inspected, and 
evaluation of the heat durability under a high temperature, was conducted. 
The evaluation results are shown in FIG. 5. 
EXAMPLE 24 
A planarizing material solution prepared in the same manner as in Example 
22, was spin-coated on a silicon substrate and then baked at 150.degree. 
C. for 10 minutes on a hot plate to form a planarized film having a 
thickness of 2.0 .mu.m. This planarized film was heated on a hot plate of 
250.degree. C., whereby shrinkage of the film was inspected, and 
evaluation of the heat durability under a high temperature, was conducted. 
The evaluation results are shown in FIG. 5. From the evaluation results, 
the heat durability imparted by the addition of the curing catalyst 
(3,3'-diaminodiphenylsulfone) was confirmed. 
EXAMPLE 25 
25 g of a methacrylic acid/n-butyl acrylate/methyl methacrylate copolymer 
obtained in the same manner as in Example 1, 4.5 g of 
hexamethoxymethylolmelamine (CYMEL (trademark) 303, manufactured by Mitsui 
Cyanamid), 5.0 g of a curing catalyst (trimellitic anhydride) and 65 g of 
diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 96.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 26 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 5.0 g of a curing 
catalyst (trimellitic anhydride) and 65 g of diethylene glycol dimethyl 
ether were mixed and dissolved, followed by filtration with a 0.2 .mu.m 
filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 27 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 2.0 g of a melamine-type heat-curing 
agent (CYMEL (trademark) 303, manufactured by Mitsui Cyanamid), 3.0 g of 
an epoxy-type heat-curing agent (EX-611, manufactured by Nagase Chemicals 
Ltd.), 5.0 g of a curing catalyst (trimellitic anhydride) and 72 g of 
diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface toughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.3% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 28 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), curing catalysts (0.7 g 
of 3,3'-diaminodiphenylsulfone and 0.5 g of trimellitic anhydride) and 72 
g of diethylene glycol dimethyl ether were mixed and dissolved, followed 
by filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.2% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 29 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, 2.0 g of a melamine-type heat-curing agent (CYMEL (trademark) 
303, manufactured by Mitsui Cyanamid), 3.0 g of an epoxy-type heat-curing 
agent (EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g of a curing 
catalyst (SI-190, manufactured by Shanshin Chemical Industry Co., Ltd.) 
and 72 g of diethylene glycol dimethyl ether were mixed and dissolved, 
followed by filtration with a 0.2 .mu.m filter to obtain a planarizing 
material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.2% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 30 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, 2.0 g of a melamine-type heat-curing agent (CYMEL (trademark) 
303, manufactured by Mitsui Cyanamid), 3.0 g of an epoxy-type heat-curing 
agent (EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g of a curing 
catalyst (3,3'-diaminodiphenylsulfone) and 65 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.2% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 31 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, 2.0 g of a melamine-type heat-curing agent (CYMEL (trademark) 
303, manufactured by Mitsui Cyanamid), 3.0 g of an epoxy-type heat-curing 
agent (EX-611, manufactured by Nagase Chemicals Ltd.), curing catalysts 
(0.7 g of 3,3'-diaminodiphenylsulfone, and 5.0 g of trimellitic anhydride) 
and 72 g of ethylene glycol dimethyl ether were mixed and dissolved, 
followed by filtration with a 0.2 .mu.m filter to obtain a planarizing 
material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.4% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 32 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 0.7 g of a curing catalyst (SI-190, 
manufactured by Shanshin Chemical Industry Co., Ltd.) and 72 g of ethylene 
glycol dimethyl ether were mixed and dissolved, followed by filtration 
with a 0.2 .mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 33 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 0.7 g of a curing catalyst 
(3,3'-diaminodiphenylsulfone) and 65 g of ethylene glycol dimethyl ether 
were mixed and dissolved, followed by filtration with a 0.2 .mu.m filter 
to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.6% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 34 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 5.0 g of a curing catalyst (trimellitic 
anhydride) and 72 g of diethylene glycol dimethyl ether were mixed and 
dissolved, followed by filtration with a 0.2 .mu.m filter to obtain a 
planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 96.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 35 
Into a 1 l four-necked flask, 25.0 g of epoxycyclohexylmethyl acrylate, 
25.0 g of n-butyl methacrylate, 10.0 g of 2,2'-azobisisobutylonitrile 
(AIBN), 5.0 g of n-dodecylmercapatne and 500 ml of dioxane were charged, 
dissolved and stirred. Then, stirring was continued under a nitrogen 
stream at 70.degree. C. for 4 hours. The reaction solution was put into 
methanol to precipitate the resin. Purification with 
tetrahydrofuran/methanol was repeated, and then vacuum drying was 
conducted at 40.degree. C. to obtain a resin powder. The obtained amount 
was 36.5 g. The weight average molecular weight as measured by GPC was 
20,000, as calculated as polystyrene; the glass transition temperature 
(Tg) was 30.degree. C.; and the epoxy equivalent was 198. 25 g of an 
epoxycyclohexylmethyl acrylate/n-butyl methacrylate copolymer thus 
obtained, 2.0 g of a melamine-type heat-curing agent (CYMEL (trademark) 
303, manufactured by Mitsui Cyanamid), 3.0 g of an epoxy-type heat-curing 
agent (EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g of a curing 
catalyst (SI-190, manufactured by Shanshin Chemical Industry Co., Ltd.) 
and 72 g of diethylene glycol dimethyl ether were mixed and dissolved, 
followed by filtration with a 0.2 .mu.m filter to obtain a planarizing 
material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 36 
25 g of an epoxycyclohexylmethyl acrylate/n-butyl methacrylate copolymer 
obtained in the same manner as in Example 35, 2.5 g of a melamine-type 
heat-curing agent (CYMEL (trademark) 303, manufactured by Mitsui 
Cyanamid), 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 0.7 g of a curing catalyst 
(3,3'-diaminodiphenylsulfone) and 72 g of diethylene glycol dimethyl ether 
were mixed and dissolved, followed by filtration with a 0.2 .mu.m filter 
to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.0% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 37 
25 g of an epoxycyclohexylmethyl acrylate/n-butyl methacrylate copolymer 
obtained in the same manner as in Example 35, 2.0 g of a melamine-type 
heat-curing agent (CYMEL (trademark) 303, manufactured by Mitsui 
Cyanamid), 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 0.7 g of a curing catalyst 
(3,3'-diaminodiphenylsulfone) and 72 g of diethylene glycol dimethyl ether 
were mixed and dissolved, followed by filtration with a 0.2 .mu.m filter 
to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.3% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 38 
25 g of an epoxycyclohexylmethyl acrylate/n-butyl methacrylate copolymer 
obtained in the same manner as in Example 35, 2.0 g of a melamine-type 
heat-curing agent (CYMEL (trademark) 303, manufactured by Mitsui 
Cyanamid), 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 5.0 g of a curing catalyst (trimellitic 
anhydride) and 72 g of diethylene glycol dimethyl ether were mixed and 
dissolved, followed by filtration with a 0.2 .mu.m filter to obtain a 
planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.5% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 39 
25 g of an epoxycyclohexylmethyl acrylate/n-butyl methacrylate copolymer 
obtained in the same manner as in Example 35, 3.0 g of an epoxy-type 
heat-curing agent (EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g 
of a curing catalyst (SI-190, manufactured by Shahshin Chemical Industry 
Co., Ltd.) and 72 g of diethylene glycol dimethyl ether were mixed and 
dissolved, followed by filtration with a 0.2 .mu.m filter to obtain a 
planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 98.3% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 40 
25 g of an epoxycyclohexylmethyl acrylate/n-butyl methacrylate copolymer 
obtained in the same manner as in Example 35, 3.0 g of an epoxy-type 
heat-curing agent (EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g 
of a curing catalyst (3,3'-diaminodiphenylsulfone) and 65 g of diethylene 
glycol dimethyl ether were mixed and dissolved, followed by filtration 
with a 0.2 .mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further in the same manner as 
in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.4% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLE 41 
25 g of an epoxycyclohexylmethyl acrylate/n-butyl methacrylate copolymer 
obtained in the same manner as in Example 35, 3.0 g of an epoxy-type 
heat-curing agent (EX-611, manufactured by Nagase Chemicals Ltd.), 5.0 g 
of a curing catalyst (trimellitic anhydride) and 72 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 95.7% (thickness: 1 .mu.m) at 400 nm. 
No change in this transparency was observed even after the heat treatment 
at 200.degree. C. for one hour. 
EXAMPLES 42 TO 45 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, an epoxy-type heat-curing agent (EX-611, manufactured by Nagase 
Chemicals Ltd.), a curing catalyst (3,3'-diaminodiphenylsulfone) and 
diethylene glycol dimethyl ether were mixed to have the composition as 
identified in Table 1 and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
TABLE 1 
______________________________________ 
Refrac- 
Composition tive 
Heat index 
curing Curing (coating 
Resin agent catalyst Sovlent film) 
______________________________________ 
Example 
PGMA.sup.1) 
EX-611 DAS.sup.2) 
Diglyme.sup.3) 
1.48 
42 25.0 g 3.0 g 1.2 g 68.0 g 
Example 
PGMA EX-611 DAS Diglyme 1.50 
43 25.0 g 3.0 g 2.1 g 70.0 g 
Example 
PGMA EX-611 DAS Diglyme 1.51 
44 25.0 g 3.0 g 3.1 g 73.0 g 
Example 
PGMA EX-611 DAS Diglyme 1.52 
45 25.0 g 3.0 g 6.2 g 80.0 g 
Reference 
PGMA EX-611 SI-190 Diglyme 1.46 
Example 5 
25.0 g 3.0 g 0.7 g 65.0 g 
______________________________________ 
.sup.1) PGMA: Polyglycidyl methacrylate 
.sup.2) DAS; 3,3diaminodiphenylsulfone 
.sup.3) Diglyme: Diethylene glycol dimethyl ether 
Each of these planarizing material solutions was spin-coated on a silicon 
substrate and baked at 150.degree. C. for 10 minutes on a hot plate to 
form a planarized film having a thickness of 2.0 .mu.m. 
The curing properties of the respective planarizing materials are shown in 
FIG. 6, and the refractive indices are shown in Table 1. 
From the results, it was confirmed that by an addition of the curing 
catalyst (3,3'-diaminodiphenylsulfone), the refractive index and the 
curing time can suitably be selected. 
EXAMPLE 46 
A planarizing material solution prepared in the same manner as in Example 
12 was spin-coated on an A1-Si substrate and then baked at 150.degree. C. 
for 10 minutes on a hot plate to form a planarized film having a thickness 
of 2.0 .mu.m. 
This planarized film was subjected to a moisture durability test in a 
temperature and moisture tester (PR-2G, manufactured by TABAI) at a 
temperature of 85.degree. C. and under a humidity of 85%. No substantial 
change was observed on the substrate surface and the planarized film even 
upon expiration of 1,000 hours under such an environment. 
EXAMPLE 47 
A planarizing material solution prepared in the same manner as in Example 
27 was spin-coated on a silicon substrate and then baked at a high 
temperature of 200.degree. C. of the curing catalyst for 10 minutes on a 
hot plate to form a planarized film having a thickness of 2.0 .mu.m. 
The surface of this planarized film was inspected in the same manner as in 
Example 1, whereby no substantial irregularities were observed on the 
planarized film, and planarization was found to be completely done. With 
respect to the solvent resistance, surface toughening which is observed if 
the curing is inadequate, was not observed when immersed in a solvent such 
as water, isopropyl alcohol, trichloroethane or xylene. Thus, it was 
confirmed that the curing catalyst effectively functioned without 
undergoing evaporation or sublimation. 
EXAMPLES 48 TO 50 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, an epoxy-type heat-curing agent (EX-611, manufactured by Nagase 
Chemicals Ltd.), a curing catalyst (SI-190, manufactured by Shanshin 
Chemical Industry Co., Ltd.) and diethylene glycol dimethyl ether were 
mixed to have the composition as identified in Table 2 and dissolved, 
followed by filtration with a 0.2 .mu.m filter to obtain a planarizing 
material solution. 
TABLE 2 
______________________________________ 
Composition 
Heat Halation- 
curing Curing preventive 
Resin agent catalyst agent Sovlent 
______________________________________ 
Example 
PGMA.sup.1) 
EX-611 SI-190 THBP.sup.2) 
Diglyme.sup.3) 
48 25.0 g 3.0 g 1.47 g 1.55 g 68 g 
Example 
PGMA EX-611 SI-190 THBP Diglyme.sup.3) 
49 25.0 g 3.0 g 0.28 g 1.48 g 70 g 
Example 
PGMA EX-611 SI-190 THBP Diglyme.sup.3) 
50 25.0 g 3.0 g 0.14 g 1.48 g 73 g 
______________________________________ 
.sup.1) PGMA: Polyglycidyl methacrylate 
.sup.2) THBP: 2,2',4,4tetrahydroxybenzophenone 
.sup.3) Diglyme: Diethylene glycol dimethyl ether 
Each of these planarizing material solutions was spin-coated on a silicon 
substrate and then baked at 150.degree. C. for from 1 to 30 minutes on a 
hot plate to form a planarized film having a thickness of 2.0 .mu.m. 
The planarized film thus obtained was immersed in methyl ethyl ketone for 5 
minutes, and the curing characteristics were evaluated by the change in 
the film thickness before and after the immersion. The results of the 
evaluation are shown in FIG. 7. 
Further, with respect to each planarizing material solution, a planarized 
film was formed in the same manner as in Example 1 except that the baking 
condition was changed as described above, and inspection of the surface 
was conducted in the same manner as in Example 1, whereby no substantial 
irregularities were observed on each planarized film, and planarization 
was found to be completely done in each case. With respect to the solvent 
resistance, no surface roughening was observed with respect to a 
planarized film having a film-remaining ratio of more than 85% when 
immersed in a solvent such as water, isopropyl alcohol, trichloroethane or 
xylene. Further, the transparency of each planarized layer in a visible 
light region was excellent, and, for example, it was from 95.0 to 96.5% 
(thickness: 1 .mu.m) at 400 nm. No change in this transparency was 
observed even after the heat treatment at 200.degree. C. for one hour. 
Further, in each case of the above curing conditions, a sufficient 
absorption was observed in the i-line region, and no substantial change in 
the spectral characteristics attributable to evaporation or sublimation of 
the halation-preventive agent, was observed, even after the heat treatment 
for one hour. Thus, it was confirmed that a wide range of process 
conditions ranging from a low temperature to a high temperature or ranging 
from a short period of time to a long period of time, can be selected. 
EXAMPLE 51 
A planarizing material solution prepared in the same manner as in Example 
17 was spin-coated on a silicon substrate and then baked within a 
temperature range from 150.degree. C. to 180.degree. C. for a curing time 
of from 1 to 30 minutes on a hot plate to form a planarized film having a 
thickness of 2.0 .mu.m. The planarized film thus obtained was immersed in 
methyl ethyl ketone for 5 minutes, and the curing characteristics were 
evaluated from the change in the film thickness before and after the 
immersion. The results of the evaluation are shown in FIG. 8. 
Further, a planarized film was formed in the same manner as in Example 1 
except that the baking condition was changed as described above, and in 
the same manner as in Example 1, inspection of the surface was conducted, 
whereby no substantial irregularities were observed on the planarized 
film, and planarization was found to be completely done. With respect to 
the solvent resistance, no surface roughening was observed with a 
planarized film having a film remaining ratio of more than 85% when 
immersed in a solvent such as water, isopropyl alcohol, trichloroethane or 
xylene. Further, the transparency of the planarized layer in a visible 
light region was excellent, and, for example, it was from 95.0 to 96.5% 
(thickness: 1 .mu.m) at 400 nm. No change in this transparency was 
observed even after the heat treatment at 200.degree. C. for one hour. 
Further, in each case of the above curing conditions, a sufficient 
absorption was observed in the i-line region, and no substantial change in 
the spectral characteristics attributable to evaporation or sublimation of 
the halation-preventive agent, was observed even after the heat treatment 
for one hour. Thus, it was confirmed that a wide range of process 
conditions ranging from a low temperature to a high temperature, or 
ranging from a short period of time to a long period of time, can be 
selected. 
EXAMPLE 52 
25 g of a cresol novolak-type epoxy resin (EOCN-1028, manufactured by 
Nippon Kayaku), 4.5 g of a melamine-type heat-curing agent (CYMEL 
(trademark) 303, manufactured by Mitsui Cyanamid), 0.7 g of a curing 
catalyst (SI-190, manufactured by Shanshin Chemical Industry Co., Ltd.) 
and 75 g of diethylene glycol dimethyl ether were mixed and dissolved, 
followed by filtration with a 0.2 .mu.m filter to obtain a planarizing 
material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 97.0% (thickness: 1 .mu.m) at 400 nm. 
Further, the transparency of this planarized layer after the heat 
treatment at 200.degree. C. for one hour, was 91.5% (thickness: 1 .mu.m). 
EXAMPLE 53 
25 g of a cresol novolak-type epoxy resin (EOCN-1028, manufactured by 
Nippon Kayaku), 6.5 g of an epoxy-type heat-curing agent (EX-611, 
manufactured by Nagase Chemicals Ltd.), 1.6 g of a curing catalyst 
(SI-190, manufactured by Shanshin Chemical Industry Co., Ltd.) and 65 g of 
diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 96.5% (thickness: 1 .mu.m) at 400 nm. 
Further, the transparency of this planarized layer after the heat 
treatment at 200.degree. C. for one hour, was 93.5% (thickness: 1 .mu.m). 
EXAMPLE 54 
25 g of a cresol novolak-type epoxy resin (EOCN-1028, manufactured by 
Nippon Kayaku), 2.0 g of a melamine-type heat-curing agent (CYMEL 
(trademark) 303, manufactured by Mitsui Cyanamid), 3.0 g of an epoxy-type 
heat-curing agent (EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g 
of a curing catalyst (SI-190, manufactured by Shanshin Chemical Industry 
Co., Ltd.) and 72 g of diethylene glycol dimethyl ether were mixed and 
dissolved, followed by filtration with a 0.2 .mu.m filter to obtain a 
planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. Further, in the same manner 
as in Example 1, inspection of the surface was conducted, whereby no 
substantial irregularities were observed on the planarized film, and 
planarization was found to be completely done. With respect to the solvent 
resistance, no surface roughening was observed when immersed in a solvent 
such as water, isopropyl alcohol, trichloroethane or xylene. Further, the 
transparency of the planarized layer in a visible light region was 
excellent, and, for example, it was 96.5% (thickness: 1 .mu.m) at 400 nm. 
Further, the transparency of this planarized layer after the heat 
treatment at 200.degree. C. for one hour, was 93.0% (thickness: 1 .mu.m). 
REFERENCE EXAMPLE 1 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g of a curing 
catalyst (1,8-diazabicyclo(5,4,0)undecane (DBU)) and 72 g of diethylene 
glycol dimethyl ether were mixed and dissolved, followed by filtration 
with a 0.2 .mu.m filter to obtain a planarizing material solution. 
Then, the storage stability was studied in the same manner as in Example 
17. As a result, with respect to the curing catalyst stored in a 
refrigerator, no substantial increase in the viscosity (thickening) was 
observed on the 14th day after the initiation of the study and it was 
possible to use it without trouble. On the other hand, with respect to the 
curing catalyst stored at room temperature, the planarizing material 
solution was completely cured upon expiration of 7 days, and it was 
impossible to use it. 
REFERENCE EXAMPLE 2 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g of a curing 
catalyst (1-isobutyl-2-methylimidazole) and 72 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. 
Then, the storage stability was studied in the same manner as in Example 
17. As a result, with respect to the curing catalyst stored in a 
refrigerator, no substantial increase in the viscosity (thickening) was 
observed on the 30th day after the initiation of the study, and it was 
possible to use it without any problem. On the other hand, with respect to 
the curing catalyst stored at room temperature, on the 7th day after the 
initiation, film forming was conducted under the same coating conditions 
as at the initial stage, whereby the film thickness increased by about two 
times, thus indicating a distinct increase of the viscosity. 
REFERENCE EXAMPLE 3 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 7.0 g of a curing 
catalyst (phthalic anhydride) and 72 g of diethylene glycol dimethyl ether 
were mixed and dissolved, followed by filtration with a 0.2 .mu.m filter 
to obtain a planarizing material solution. 
Then, a planarized film was formed in the same manner as in Example 46. 
Further, in the same manner as in Example 1, inspection of the surface was 
conducted, whereby no substantial irregularities were observed on the 
planarized film, and planarization was. found to be completely done. With 
respect to the solvent resistance, no surface roughening was observed when 
immersed in a solvent such as water, isopropyl alcohol, trichloroethane or 
xylene. 
On the other hand, formation of the planarized film was conducted by 
changing the conditions for forming a planarized film to 200.degree. C. 
for 5 minutes, whereby a decrease in the film thickness due to flowing of 
the planarized layer was observed, although the formation of the 
planarized film was good. Further, also with respect to the solvent 
resistance, surface roughening and dissolution of the coating film were 
observed when immersed in a solvent such as isopropyl alcohol, 
trichloroethane or xylene. 
Further, by the IR (infrared absorption spectrum) measurement, absorption 
at 1,780 cm.sup.-1 and 1,830-1,860 cm.sup.-1 attributable to a carbonyl 
group of an anhydride ring was examined before and after the curing 
treatment, whereby the absorption was found to decrease substantially, 
while no new absorption or shift attributable to the curing reaction was 
found to appear. Thus, evaporation or sublimation of the curing catalyst 
during the curing treatment was confirmed. 
REFERENCE EXAMPLE 4 
25 g of a glycidyl methacrylate/n-butyl methacrylate copolymer obtained in 
the same manner as in Example 6, 3.0 g of an epoxy-type heat-curing agent 
(EX-611, manufactured by Nagase Chemicals Ltd.), 0.7 g of a curing 
catalyst (1-isobutyl-2-methylimidazole) and 72 g of diethylene glycol 
dimethyl ether were mixed and dissolved, followed by filtration with a 0.2 
.mu.m filter to obtain a planarizing material solution. Then, a 
moisture-durability test was conducted in the same manner as in Example 
39. Upon expiration of 1,000 hours, the surface was observed, whereby 
formation of many voids and a color change were observed on an A1-Si 
substrate although no substantial change was observed on a silicon 
substrate. 
REFERENCE EXAMPLE 5 
25 g of a glycidyl methacrylate polymer obtained in the same manner as in 
Example 8, 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 0.7 g of a curing catalyst (SI-190, 
manufactured by Shanshin Chemical Industry Co., Ltd.) and 65 g of 
diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
This planarizing material solution was spin-coated on a silicon substrate 
and then baked at 150.degree. C. for 10 minutes on a hot plate to form a 
planarized film having a thickness of 2.0 .mu.m. 
The refractive index of this planarized film was measured in the same 
manner as in Examples 42 to 45. The results are shown in Table 1. 
REFERENCE EXAMPLE 6 
A planarizing material solution prepared in the same manner as in Example 9 
was spin-coated on a silicon substrate and then baked at 150.degree. C. 
for 10 minutes on a hot plate to form a planarized film having a thickness 
of 2.0 .mu.m. 
This planarized film was subjected to a heat durability test under a high 
temperature in the same manner as in Example 23. The results are shown in 
FIG. 5. 
COMATIVE EXAMLE 1 
Into a 1 l four-necked flask, 24.5 g of methacrylic acid, 12.0 g of n-butyl 
methacrylate, 13.5 g of methyl methacrylate, 4.0 g of 
2,2'-azobisisobutylonitrile (AIBN) and 500 ml of dioxane were charged, 
dissolved and stirred. Then, stirring was continued under a nitrogen 
stream at 70.degree. C. for 6 hours. The reaction solution was put into 
methanol to precipitate the resin. Purification was repeated with 
tetrahydrofuran/methanol, and then vacuum drying was conducted at 
40.degree. C. to obtain a resin powder. The obtained amount was 42.0 g. 
The weight average molecular Weight as measured by GPC was 260,000 as 
calculated as polystyrene; the glass transition temperature (Tg) was 
145.degree. C.; and the acid value calculated after titration by a 
potentiometer was 351. 25 g of a methacrylic acid/n-butyl acrylate/methyl 
methacrylate copolymer having a high molecular weight and a high Tg, thus 
obtained, 4.4 g of hexamethoxymethylolmelamine (CYMEL (trademark) 303, 
manufactured by Mitsui Cyanamid) and 83 g of ethyl lactate were mixed and 
dissolved, followed by filtration with a 0.2 .mu.m filter to obtain a 
planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. However, even after the 
planarizing step, a level difference of from 1.0 to 1.5 .mu.m remained, 
and desired flatness was not obtained. The same evaluation was attempted 
by raising the baking temperature, but the level difference of the same 
degree still remained and desired flatness was not obtained, although a 
certain improvement was observed. 
COMATIVE EXAMPLE 2 
25 g of a methacrylic acid/n-butyl acrylate/methyl methacrylate copolymer 
obtained in the same manner as in Comparative Example 1, 6.5 g of an 
epoxy-type heat-curing agent (EX-611, manufactured by Nagase Chemicals 
Ltd.), 1.6 g of a curing catalyst (SI-190, manufactured by Shanshin 
Chemical Industry Co., Ltd.) and 77 g of diethylene glycol dimethyl ether 
were mixed and dissolved, followed by filtration with a 0.2 .mu.m filter 
to obtain a planarizing material solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. However, even after the 
planarizing step, a level difference of from 1.0 to 1.5 .mu.m remained, 
and desired flatness was not obtained. Further, the same evaluation was 
attempted by raising the baking temperature, but the level difference of 
the same degree still remained, and desired flatness was not obtained, 
although a certain improvement was observed. 
COMATIVE EXAMPLE 3 
25 g of a methacrylic acid/n-butyl acrylate/methyl methacrylate copolymer 
obtained in the same manner as in Comparative Example 1, 2.0 g of 
hexamethoxymethylolmelamine (CYMEL (trademark) 303, manufactured by Mitsui 
Cyanamid), 3.0 g of an epoxy-type heat-curing agent (EX-611, manufactured 
by Nagase Chemicals Ltd.), 0.7 g of a curing catalyst (SI-190, 
manufactured by Shanshin Chemical Industry Co., Ltd.) and 72 g of 
diethylene glycol dimethyl ether were mixed and dissolved, followed by 
filtration with a 0.2 .mu.m filter to obtain a planarizing material 
solution. 
A planarized film was formed in the same manner as in Example 1 except that 
this planarizing material solution was used. However, even after the 
planarizing step, a level difference of from 1.0 to 1.5 .mu.m remained, 
and desired flatness was not obtained. Further, the same evaluation was 
attempted by raising the baking temperature, but the level difference of 
the same degree still remained, and desired flatness was not obtained, 
although a certain improvement was observed. 
COMATIVE EXAMPLE 4 
A planarized film was formed in the same manner as in Example 1 except that 
a heat-curing agent (a melamine-type heat-curing agent or an epoxy-type 
heat-curing agent) was not incorporated. Formation of a planarized film 
was good, but when the planarized film was subjected to a heating test at 
200.degree. C. for 5 minutes on a hot plate, a decrease in the film 
thickness due to flowing of the planarized layer, was observed. Further, 
also with respect to the solvent resistance, surface roughening, swelling 
and a change in the film thickness were observed when immersed in a 
solvent such as isopropyl alcohol, trichloroethane or xylene. 
As is apparent from the foregoing description, the planarizing material of 
the present invention comprising a resin capable of having its practical 
temperature for a planarizing step set at a level lower than 200.degree. 
C., a heat-curing agent, etc., has heat durability and solvent resistance 
and is capable of presenting a high level of flatness. Further, if a 
halation-preventing function is required for the planarizing material, by 
a combination of the resin with a halation-preventive agent having a 
functional group so that it is taken into the system by an addition 
reaction, a halation-preventing function can effectively be obtained 
without evaporation or sublimation even under a high temperature during 
the planarizing/curing step. Further, the planarizing material of the 
present invention has a feature that it has excellent transparency to a 
visible light of at least 400 nm. 
On the other hand, the planarizing method using the planarizing material of 
the present invention can be a simple method having the cumbersomeness of 
conventional process steps reduced and thus has a merit that the 
productivity can thereby be improved. 
Thus, the planarizing material and the planarizing method of the present 
invention is useful for the production of charge coupled devices with 
highly densified picture elements, liquid crystal display devices or 
semiconductor integrated circuits.