Apparatus for and method of cleaning substrate

A substrate rinsing apparatus of a non-contact type having a high rinsing ability. An ultrasonic rinsing nozzle and a high-pressure rinsing nozzle are both disposed within the same rinsing apparatus. The ultrasonic rinsing nozzle ejects ultrasonic rinsing liquid as a curtain through a slit, while the high-pressure rinsing nozzle ejects a high-pressure rinsing jet toward the ultrasonic rinsing liquid which is ejected toward a substrate. Not only is foreign matter removed by ultrasonic rinsing, but foregoing matter is removed by the high-pressure rinsing jet and is carried away by a flow of the ultrasonic rinsing liquid and washed off the substrate toward a downstream side of rotation of the substrate.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an improved substrate cleaning technique, 
and more particularly to a technique for enabling both an ability of 
removing a foreign matter which is on a surface of a substrate and an 
ability of discharging a removed foreign matter from the surface of the 
substrate. 
2. Description of the Prior Art 
As well known, surface processing using various types of processing liquid 
is performed on a substrate such as a glass substrate for a liquid crystal 
display apparatus and a semiconductor wafer. Following such processing, it 
is necessary to remove remaining processing liquid from a substrate. It is 
also important to remove particles which are adhered to the surface of the 
substrate. For removal of such a foreign matter, the substrate is 
subjected to a cleaning process. Cleaning methods are generally divided 
into chemical cleaning and physical cleaning. 
Chemical cleaning includes one using pure water, one using neutral or 
alkaline cleaning liquid, one using ozone water which is obtained by 
solving ozone in cleaning liquid, etc. Such chemical cleaning, being based 
on chemical solving, is effective for removal of a relatively fine foreign 
matter and a foreign matter which is chemically bonded to a substrate, but 
is not effective for removal of a relatively large foreign matter. For 
this reason, physical cleaning is often performed in addition to chemical 
cleaning. 
Meanwhile, there are various types of methods of physical cleaning. As each 
of the methods has both advantages and disadvantages, sufficient physical 
cleaning is difficult with one method alone. Hence, in many cases, more 
than one physical cleaning method are combined to achieve the desired 
level of cleaning. 
Under the circumstance, parallel use of a plurality of physical cleaning 
methods within one apparatus has been proposed. For example, Japanese 
Patent Laid Open Official Gazette No. 7-86218 discloses an apparatus which 
simultaneously performs both a brush-cleaning method with a rotating brush 
and an ultrasonic cleaning method with ultrasonically vibrated liquid. 
Execution of a plurality of cleaning methods within one apparatus as 
disclosed by Japanese Patent Laid Open Official Gazette No. 7-86218 is 
related to a time which is needed for cleaning. In other words, as 
substrates have become larger in recent years, the demand for a shortened 
cleaning time has been mounting. If cleaning apparatuses of different 
methods are arranged linearly and cleaning is performed serially by these 
cleaning apparatuses, the cleaning time which is available for each 
cleaning apparatus is shortened and therefore its cleaning ability is 
reduced. 
However, such an apparatus for a brush-cleaning method as that disclosed by 
Japanese Patent Laid Open Official Gazette No. 7-86218 has another 
problem. That is, although a brush-cleaning method has an excellent 
ability to remove a foreign matter, as being physical cleaning which 
requires a physical contact, the method gives damage such as a flaw to a 
surface of a substrate. 
SUMMARY OF THE INVENTION 
In accordance with such principles, the present invention is defined as 
comprising the following means and structures. 
&lt;First Invention&gt; 
According to a first invention, an apparatus for cleaning a substrate 
comprises: 
a) ultrasonic cleaning means for emitting an ultrasonic wave onto liquid 
while injecting the liquid toward the substrate so as to perform 
ultrasonic rinsing on the substrate; and b) high-pressure cleaning means 
which is disposed at a different position from the ultrasonic cleaning 
means, the high-pressure cleaning means jetting out high-pressure liquid 
toward the substrate so as to perform high-pressure rinsing on the 
substrate, and the substrate cleaning apparatus is structured so as to 
perform combined rinsing combining the ultrasonic rinsing and the 
high-pressure rinsing on the substrate. 
&lt;Second Invention&gt; 
According to a second invention, the substrate cleaning apparatus of the 
first invention further c) substrate rotating means for rotating the 
substrate in a predetermined direction, so as to perform the combined 
rinsing while rotating the substrate. This is an application to a 
so-called spin scrubber. 
&lt;Third Invention&gt; 
According to a structure of a third invention, in the substrate cleaning 
apparatus of the second invention, the ultrasonic cleaning means includes 
a-1) an ultrasonic rinsing nozzle for injecting the liquid which is 
subjected to the ultrasonic wave, through a slit, toward an ultrasonic 
rinsing line which is defined on a surface-to-be-cleaned of the substrate, 
and the high-pressure cleaning means includes b-1) a high-pressure rinsing 
nozzle for jetting out high-pressure liquid toward a high-pressure rinsing 
spot which is defined on the surface-to-be-cleaned of the substrate. 
Although high-pressure rinsing as well uses a slit as during ultrasonic 
rinsing, for valid rinsing at a relatively low jet liquid pressure and for 
maintaining ultrasonic oscillation of rinsing liquid to a maximum extent, 
jetting out of high-pressure liquid as a spot as in the structure of the 
third invention is preferable. 
&lt;Fourth Invention&gt; 
According to a structure of a fourth invention, the substrate cleaning 
apparatus of the third invention further comprises d) high-pressure 
rinsing nozzle swinging means for swinging the high-pressure rinsing 
nozzle along a locus which passes above the center of rotation of the 
substrate and which is substantially parallel to a surface of the 
substrate. 
When the high-pressure rinsing nozzle swings in this manner, a 
bubbling-induced cavitation effect is created inside the rinsing liquid 
which is supplied onto a surface of the substrate. This further enhances 
the cleaning ability. 
&lt;Fifth Invention&gt; 
According to a structure of a fifth invention, in the substrate cleaning 
apparatus of the fourth invention, the high-pressure rinsing spot is set 
at such a position in the vicinity of the ultrasonic rinsing line so as to 
scan the substrate before the ultrasonic rinsing line scans the substrate 
as the substrate is rotated. 
An advantage according to the structure of the fifth invention will be 
described in detail later, in relation to preferred embodiments. 
&lt;Sixth Invention&gt; 
According to a structure of a sixth invention, in the substrate cleaning 
apparatus of the fifth invention, the high-pressure rinsing spot is set 
shifted toward a farther one of the both end points of the ultrasonic 
rinsing line which is farther from the center of rotation of the 
substrate. 
An advantage according to the structure of the sixth invention as well will 
be described in detail later, in relation to preferred embodiments. 
&lt;Seventh To Twelfth Inventions&gt; 
These inventions are method inventions which respectively correspond to the 
first to the sixth apparatus inventions. As structures and functions of 
these inventions are understandable from the description above on the 
apparatus inventions and a description in the following on preferred 
embodiments, a redundant description will be simply omitted. 
&lt;Thirteenth Invention&gt; 
According to a structure of a thirteenth invention, the substrate cleaning 
apparatus of the first invention further comprises c) moving means for 
moving said substrate or both the ultrasonic cleaning means and the 
high-pressure cleaning means relative to each other, and is characterized 
in that rinse-scanning is performed on the substrate while performing the 
translating. 
&lt;Fourteenth Invention&gt; 
According to a structure of a fourteenth invention, in the substrate 
cleaning apparatus of the thirteenth invention, the ultrasonic cleaning 
means includes a-1) an ultrasonic rinsing nozzle for injecting the liquid 
which is subjected to the ultrasonic wave, through a slit, toward an 
ultrasonic rinsing line which is defined on a surface-to-be-cleaned of the 
substrate, and the high-pressure cleaning means includes b-1) a 
high-pressure rinsing nozzle for jetting out high-pressure liquid toward 
an arrangement of high-pressure rinsing spots which is defined on the 
surface-to-be-cleaned of the substrate. 
That is, in this apparatus, ultrasonic rinsing is realized in the form of a 
line and high-pressure rinsing is realized in the form of arranged points 
on the surface-to-be-cleaned of the substrate. 
&lt;Fifteenth Invention&gt; 
According to a structure of a fifteenth invention, the substrate cleaning 
apparatus of the fourteenth invention further comprises d) high-pressure 
rinsing nozzle swinging means for swinging the high-pressure rinsing 
nozzle along the direction of the arrangement of the high-pressure rinsing 
spots. 
&lt;Sixteenth Invention&gt; 
According to a structure of a sixteenth invention, in the substrate 
cleaning apparatus of the fifteenth invention, there are a plurality of 
the high-pressure rinsing nozzles which are disposed on the both sides of 
the ultrasonic rinsing nozzle, so that there are a plurality of the 
arrangements of the high-pressure rinsing spots which are defined on the 
both sides of the ultrasonic rinsing line. 
Of various preferred embodiments described later, a substrate cleaning 
apparatus 100 as that shown in FIG. 13 is a typical example of an 
application of the sixteenth and the seventeenth inventions. 
&lt;Seventeenth Invention&gt; 
According to a structure of a seventeenth invention, in the substrate 
cleaning apparatus of the sixteenth invention, the ultrasonic rinsing 
nozzle injects the liquid approximately perpendicularly to the 
surface-to-be-cleaned of the substrate, and the high-pressure rinsing 
nozzles each jet out the high-pressure liquid at an angle which is 
approximately the same or away from the direction in which the liquid is 
injected from the ultrasonic rinsing nozzle. 
&lt;Eighteenth Invention&gt; 
According to a structure of an eighteenth invention, in the substrate 
cleaning apparatus of the fifteenth invention, the substrate is 
transported relative to the ultrasonic cleaning means and the 
high-pressure cleaning means in one predetermined direction, and the 
arrangement of the high-pressure rinsing spots are set at such positions 
so as to scan the substrate in the one predetermined direction before the 
ultrasonic rinsing line scans the substrate. 
Of various preferred embodiments described later, a substrate cleaning 
apparatus 200 as that shown in FIGS. 2A and 2B is a typical example of an 
application of the eighteenth and the nineteenth inventions. 
&lt;Nineteenth Invention&gt; 
According to a structure of a nineteenth invention, in the substrate 
cleaning apparatus of the eighteenth invention, the ultrasonic rinsing 
nozzle injects the liquid at an angle which is inclined toward the 
predetermined direction with respect to the surface-to-be-cleaned of the 
substrate, and of the both sides of the ultrasonic rinsing nozzle, the 
high-pressure rinsing nozzles are disposed only on one side which 
corresponds to an opposite direction to the predetermined direction in 
which the substrate is transported, and the high-pressure rinsing nozzles 
each jet out the high-pressure liquid at an angle which is approximately 
the same or more inclined than the direction in which the liquid is 
injected from the ultrasonic rinsing nozzle. 
&lt;Twentieth To Twenty-Second Inventions&gt; 
These inventions are method inventions which respectively correspond to the 
thirteenth to the fifteenth apparatus inventions. As structures and 
functions of these inventions are understandable from the description 
above on the apparatus inventions and a description in the following on 
preferred embodiments, a redundant description will be simply omitted. 
As described above, according to the first to the twenty-second inventions, 
as combined rinsing combining ultrasonic rinsing and high-pressure rinsing 
is performed, synergy of a foreign matter removing ability and a foreign 
matter discharging ability, i.e., advantages of the respective rinsing 
methods enhances the rinsing ability of rinsing a substrate. 
Particularly because a foreign matter which is removed by the high-pressure 
rinsing is swiftly discharged by an affluent quantity of the ultrasonic 
rinsing liquid, the cleaning ability is further better than where the 
rinsing methods are performed separately by separate apparatuses. 
Further, since combined rinsing according to the present invention is 
combination of non-contact type rinsing methods, the synergy of the 
rinsing methods realizes a sufficient rinsing ability, it is not necessary 
to excessively increase the pressure for high-pressure rinsing. Hence, 
there is no damage such as a flow to a substrate and no uneven rinsing. 
When high-pressure rinsing is performed while swinging as in the fourth, 
the tenth, the fifteenth and the twenty-second inventions in particular, a 
bubbling-induced cavitation effect is created inside the rinsing liquid 
which is supplied onto a surface of the substrate. This further enhances 
the rinsing ability. 
Further, when the high-pressure rinsing spot is defined in front of the 
ultrasonic rinsing line as the substrate is rinsed while rotated as in the 
fifth and the eleventh inventions, it is possible to appropriately set the 
quantity of the ultrasonic rinsing liquid at a high-pressure rinsing 
position, and therefore, high-pressure rinsing is performed efficiently 
through a layer of the ultrasonic rinsing liquid. 
In addition, when the high-pressure rinsing spot is set shifted toward a 
farther one of the both end points of the high-pressure rinsing line which 
is farther from the center of rotation of the substrate as in the sixth 
and the twelfth inventions, it is possible to rinse without wasting the 
rinsing liquid. 
Still further, when the high-pressure rinsing nozzle jets out the 
high-pressure liquid at an angle which is approximately the same or more 
inclined than the direction for injecting the ultrasonic rinsing liquid as 
in the seventeenth and the nineteenth inventions, it is possible to 
prevent a foreign matter which is removed by the high-pressure rinsing 
from returning toward the ultrasonic rinsing nozzle. Hence, both the 
foreign matter removing ability and the foreign matter discharging ability 
are realized more efficiently. 
Accordingly, an object of the present invention is to provide for a 
substrate rinsing technique which exhibits an excellent rinsing ability 
without damaging a substrate and while maintaining time-effective rinsing. 
The present invention particularly aims at enabling both an ability of 
removing a foreign matter which is adhered to a surface-to-be-cleaned of a 
substrate and an ability of discharging a removed foreign matter outside a 
substrate. 
As herein termed, "a foreign matter" generally refers to an object which is 
to be removed by cleaning, including residual processing liquid which is 
applied prior to cleaning and particles. 
These and other objects, features, aspects and advantages of the present 
invention will become more apparent from the following detailed 
description of the present invention when taken in conjunction with the 
accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
1. Principles For Solving Problems 
To achieve the objects described earlier, the present invention requires 
combined rinsing which includes ultrasonic rinsing method and a 
high-pressure rinsing method. Before describing the combined rinsing, 
advantages and disadvantages of the two rinsing methods will be described. 
&lt;1-1. Advantage And Disadvantage Of Ultrasonic Rinsing&gt; 
First, since ultrasonic rinsing methods perform rinsing while supplying a 
relatively large quantity of liquid, the ultrasonic rinsing methods have 
an excellent function (i.e., liquid replaceability) of quickly supplying 
new rinsing liquid onto a substrate and externally discharging foreign 
matter from a surface of the substrate together with the rinsing liquid. 
However, as ultrasonic rinsing does not have a very strong function of 
removing foreign matter, ultrasonic rinsing alone cannot easily remove 
foreign matter which adheres to the surface of the substrate. 
&lt;1-2. Advantage and Disadvantage Of High-Pressure Rinsing&gt; 
On the other hand, the high-pressure rinsing method is a method which 
removes foreign matter by means of the dynamic effect of a high-pressure 
rinsing jet, and therefore, is excellent in removing foreign matter. 
However, since a relatively small quantity of liquid is ejected according 
to this type of method, high-pressure rinsing alone is poor in terms of 
liquid replaceability. Thus, this type of method still has a problem that 
a foreign matter will adhere again to the surface of the substrate. 
Although the problem of foreign matter again adhering to the surface is 
solved to a certain extent if the emission pressure of a high-pressure 
rinsing jet is increased, an increased emission pressure tends to damage a 
substrate surface, leading to new problems such as a flaw to a circuit 
pattern which is formed on the surface of the substrate, and uneven 
rinsing. 
&lt;1-3. Advantage Of Combined Rinsing Which Combines Ultrasonic Rinsing And 
High-Pressure Rinsing&gt; 
For the reason described above, the present invention proposes a structure 
for performing combined rinsing which combines an ultrasonic rinsing 
method and a high-pressure rinsing method. In the proposed structure, the 
flow of a relatively large quantity of liquid which is supplied for 
ultrasonic rinsing discharges not only foreign matter which is removed by 
ultrasonic rinsing but also foreign matter which is removed by 
high-pressure rinsing. Hence, it is possible to prevent re-adhering of 
removed foreign matter to a surface of a substrate while utilizing a 
powerful rinsing ability of high-pressure rinsing. This is a newly-created 
unique function which is obtained by combining high-pressure rinsing and 
ultrasonic rinsing. 
Further, the combination of high-pressure rinsing and ultrasonic rinsing 
enhances an overall ability for removing foreign matters. As this 
eliminates the need to very much increase the pressure of a high-pressure 
rinsing jet during high-pressure rinsing, damage by a high-pressure 
rinsing jet to a substrate and uneven rinsing are prevented. 
In short, according to the present invention, synergy of a foreign matter 
removing ability of high-pressure rinsing and a foreign matter discharging 
ability of ultrasonic rinsing creates an effect which is better than the 
sum of these two functions. 
2. First Preferred Embodiment 
&lt;2-1. Brief Description Of Overall Mechanism And Operation&gt; 
FIG. 1 is an essential perspective view of a substrate cleaning apparatus 
100 which represents a first preferred embodiment which is common to the 
first to the twelfth inventions. The substrate cleaning apparatus 100 is 
structured to perform ultrasonic rinsing and high-pressure rinsing at the 
same time, i.e., combined rinsing, to a surface of a glass substrate 1 for 
a liquid crystal display apparatus. The substrate cleaning apparatus 100 
is classified as a so-called spin scrubber. 
In FIG. 1, a chuck for holding the substrate 1 includes a cross-shaped arm 
2. The substrate 1 is received at four corners by a plurality of pins 3 
which are disposed to tips of the arm 2, and the substrate 1 is rotated in 
a horizontal plane in a direction .theta..sub.1 in FIG. 1. A drive source 
for such rotation is a motor M.sub.1. For convenience of illustration, 
FIG. 1 does not show how the motor M.sub.1 is linked to the chuck. 
To clean the substrate 1, a combined cleaning mechanism 50 is disposed for 
performing high-pressure rinsing and ultrasonic rinsing. Within the 
combined cleaning mechanism 50, an arm 52 is linked to a column 51 so that 
the column 51 and the arm 52 are revolvable when driven by a motor M.sub.2 
in a direction .theta..sub.2 (FIG. 1 does not show how the motor M.sub.2 
is linked to the column 51 and the arm 52.). An ultrasonic rinsing nozzle 
10 is fixed to a tip of the arm 52. The ultrasonic rinsing nozzle 10 has 
the subsequently discovered internal structure, so that an ultrasonic wave 
forces emitted rinsing liquid in the form of a curtain from a slit onto a 
surface of the substrate 1. 
FIG. 2A is a conceptual front view of the ultrasonic rinsing nozzle 10 in 
perspective, while FIG. 2B is a conceptual (partial) plan view of the 
ultrasonic rinsing nozzle 10 in perspective. In the ultrasonic rinsing 
nozzle 10, an ultrasonic wave is emitted from an ultrasonic wave 
oscillator 11 onto rinsing liquid F which is ejected through a rinsing 
liquid inlet 12 and the rinsing liquid F is jetted out through a slit 13 
which is disposed beneath. The length of the slit 13 is 80 mm and the 
width thereof is 2 mm, for instance. 
A high frequency oscillating voltage is supplied to the ultrasonic wave 
oscillator 11. Preferably, the frequency of the supplied voltage is in the 
range of: 
0.8 MHz-2.0 MHz 
More preferably, the range is: 
1.2 MHz-1.8 MHz 
The rinsing liquid inlet 12 is linked to a resin tube 15. The tube 15 is 
passed through the arm 52 (See FIG. 1) and the column 51 and linked to a 
rinsing liquid supply part through a spiral tube 60. 
The quantity of the rinsing liquid F to be supplied is preferably in the 
range of: 
7-10 liters/min 
A linkage arm 53 extends from the ultrasonic rinsing nozzle 10 of FIG. 1, 
and a high-pressure rinsing nozzle 20 is attached to a tip of the linkage 
arm 53 through a connecting member 54. A small hole (having a diameter of 
0.2 mm, for instance) of a circular shape in cross section is formed in a 
tip of the high-pressure rinsing nozzle 20, so that a high-pressure 
rinsing jet J, which is supplied through a resin tube 25, is ejected 
almost as a beam. The tube 25 is passed through the arm 52 and the column 
51, and is linked to the rinsing liquid supply part through the spiral 
tube 60. 
The pressure of the high-pressure rinsing liquid which is supplied to the 
high-pressure rinsing nozzle 20 is preferably in the range of: 
5 kg/cm.sup.2 -15 kg/cm.sup.2 
Further preferably, the pressure is in the range of: 
8 kg/cm.sup.2 -10 kg/cm.sup.2 
An example of a desired quantity of the high-pressure rinsing liquid to be 
supplied is: 
0.05 liters/min 
The connecting member 54 is revolvable in a direction .phi..sub.1 with 
respect to the linkage arm 53, while the high-pressure rinsing nozzle 20 
is revolvable in a direction .phi..sub.2 with respect to the connecting 
member 54. Hence, the direction of the high-pressure rinsing nozzle 20 is 
optionally adjustable by manual adjustment. Manual adjustment is executed 
in a preparatory stage prior to actual rinsing. During rinsing with the 
combined cleaning mechanism 50, the high-pressure rinsing nozzle 20 is 
fixed in an adjusted direction. 
Now, brief description will be given on a mechanical operation of the 
apparatus 100. Details of positional relationship between ultrasonic 
rinsing and high-pressure rinsing and effects of ultrasonic rinsing and 
high-pressure rinsing will be subsequently described. 
Before the substrate 1 is set in the substrate cleaning apparatus 100, the 
arm 52 and the members fixed thereto are retracted in the direction of an 
imaginary line in FIG. 1. Upon mounting of the substrate 1 by a transport 
robot onto the cross-shaped arm 2 of the chuck, the arm 52 and the members 
fixed thereto, revolved in the .theta..sub.2 direction, are moved to the 
solid-line positions in FIG. 1. As the substrate 1 starts to rotate at a 
high speed, the ultrasonic rinsing nozzle 10 ejects the ultrasonic rinsing 
liquid and the high-pressure rinsing nozzle 20 jets out the high-pressure 
rinsing jet J while the arm 52 reciprocally swings in the .theta..sub.2 
direction, which in turn swings the ultrasonic rinsing nozzle 10 and the 
high-pressure rinsing nozzle 20 back and forth along an arc locus within a 
horizontal plane above the substrate 1. In this manner, respective 
portions in the top surface of the substrate 1 are scanned by combined 
rinsing combining ultrasonic rinsing and high-pressure rinsing. 
Upon rinsing, the respective nozzles 10 and 20 are retracted together with 
the arm 52. Spinning of the substrate 1 is stopped after residual rinsing 
liquid remaining on the substrate 1 is drained by rotation (i.e., by spin 
dry). In a reversed process to that for setting in the substrate, the 
substrate 1 is unloaded. 
Although not shown in FIG. 1, rinsing liquid which is drained off from the 
substrate 1 is collected by a cup and discharged. 
&lt;2-2. Positional Relationship Between Ultrasonic Rinsing And High-Pressure 
Rinsing&gt; 
FIG. 3 is an enlarged view of the ultrasonic rinsing nozzle 10 as it is 
viewed from a direction which is perpendicular to an elongated direction 
of the ultrasonic rinsing nozzle 10, and FIG. 4 is a view showing a 
positional relationship as it is viewed in perspective from above. 
Referring to FIG. 4 the ultrasonic rinsing liquid from the ultrasonic 
rinsing nozzle 10 is ejected approximately perpendicularly as a curtain 
onto the top surface of the substrate 1. The position at which the rinsing 
liquid in the form of a curtain hits the surface of the substrate 1 
defines an imaginary line (i.e., ultrasonic rinsing line) L. While the 
substrate 1 rotates in the .theta..sub.1 direction in FIG. 1, although the 
substrate 1 moves relatively in a direction R in FIG. 4 immediately below 
the nozzles 10 and 20, the ultrasonic rinsing line L extends in a 
direction which crosses the rotation direction R of the substrate 1. 
Further, as shown in FIG. 3, the rinsing liquid F ejected through the slit 
13 of the ultrasonic rinsing nozzle 10, after widened to a certain extent, 
is carried by the rotation of the substrate mainly toward a downstream 
side (which is the left-hand side in FIG. 3). 
On the other hand, as shown in FIGS. 3 and 4, an imaginary high-pressure 
rinsing spot P, which is an ejection target point for jetting out the 
high-pressure rinsing jet J, is set at such a position in the vicinity of 
the ultrasonic rinsing line L so as to scan the substrate 1 before the 
ultrasonic rinsing line L scans the substrate 1 as rotation R 
(.theta..sub.1 in FIG. 1) of the substrate 1 progresses. A distance D (See 
FIG. 3) between the imaginary high-pressure rinsing spot P and the 
ultrasonic rinsing line L is 3-10 mm, for instance, so that the 
high-pressure rinsing spot P is set within an area in which the rinsing 
liquid F ejected through the slit 13 of the ultrasonic rinsing nozzle 10 
exists. Such adjustment of the direction is realized by adjusting the 
angle of the high-pressure rinsing nozzle 20 through the connecting member 
54. 
Further, between both end points E.sub.1 and E.sub.2 of the ultrasonic 
rinsing line L, the high-pressure rinsing spot P is set shifted toward the 
end point E.sub.1. As shown in FIG. 5 which conceptually illustrates 
oscillation of the combined rinsing mechanism 50, end point E.sub.1 is a 
farther one of the both end points E.sub.1 and E.sub.2 of the ultrasonic 
rinsing line L from the center of rotation CP of the substrate 1. More 
specifically, the first preferred embodiment requires that the 
high-pressure rinsing spot P is set shifted toward the end point E.sub.1. 
The reason for this will be described in detail later. 
&lt;2-3. Basic Effect Of Combined Rinsing&gt; 
A basic effect of combined rinsing of combining the ultrasonic rinsing and 
high-pressure rinsing according to the first preferred embodiment is as 
described below. (A description will be given later on swinging scanning.) 
As shown in FIG. 3, an optional portion on the substrate 1 moves in the 
direction R as the substrate rotates, reaching somewhere below and near 
the ultrasonic rinsing nozzle 10. This subjects the optional portion to 
rinsing by the high-pressure rinsing jet J, first. Meanwhile, at the 
destination of the high-pressure rinsing jet J, there is the ultrasonic 
rinsing liquid F which is supplied from the ultrasonic rinsing nozzle 10. 
Hence, foreign matter which is removed by the high-pressure rinsing jet J 
is carried away by the flow of the ultrasonic rinsing liquid F toward a 
downstream side (which is the left-hand side in FIG. 3) and is then washed 
away outside from the surface of the substrate 1. 
The portion which is processed by such high-pressure rinsing, as the 
substrate 1 rotates, next moves to immediately below the slit 13 of the 
ultrasonic rinsing nozzle 10, so as to be subjected to ultrasonic rinsing 
at that point to thereby remove a foreign matter which was not removed by 
high-pressure rinsing. A foreign matter which is removed by ultrasonic 
rinsing as well is carried away by the flow of the ultrasonic rinsing 
liquid toward the downstream side and washed away outside from the surface 
of the substrate 1. 
In this manner, not only the substrate 1 is subjected to the respective 
rinsing effects of high-pressure rinsing and ultrasonic rinsing, but also 
a foreign matter which is removed by high-pressure rinsing is ejected 
outside the substrate 1 together with a foreign matter which is removed by 
ultrasonic rinsing, thereby preventing removed foreign matters from 
adhering to the substrate 1 once again. As a result, the rinsing effect is 
larger than a sum of the rinsing abilities of the two types of rinsing. 
By the way, the high-pressure rinsing spot P is not set on the ultrasonic 
rinsing line L but is set toward an upstream side (which is the right-hand 
side in FIG. 3) with the distance D in the first preferred embodiment. 
This is because the efficiency of high-pressure rinsing is improved as the 
quantity of flow of the ultrasonic rinsing liquid is appropriate on the 
upstream side to the ultrasonic rinsing line L and as the high-pressure 
rinsing jet J reaches the surface of the substrate 1 without fail through 
the layer of the ultrasonic rinsing liquid F. 
Further, according to the first preferred embodiment, the ultrasonic 
rinsing nozzle 10 injects the ultrasonic rinsing liquid F approximately 
perpendicularly to the surface of the substrate 1 (i.e., a 
surface-to-be-cleaned). This is related to a fact that spin-type cleaning 
of a substrate generally requires to rotate a substrate at high rotation 
speed and to swing a rinsing mechanism. That is, in general, if ultrasonic 
rinsing liquid is injected approximately perpendicularly to a 
surface-to-be-cleaned, splash of the ultrasonic rinsing liquid at the 
surface-to-be-cleaned jumps back into an ultrasonic rinsing nozzle and 
damages an ultrasonic oscillator of the nozzle. To deal with this, an 
ultrasonic rinsing nozzle is used at an angle with respect to a 
surface-to-be-cleaned in many cases. However, in the case of the substrate 
used in the first preferred embodiment which is rotated at a high speed, 
splash of the ultrasonic rinsing liquid at the surface-to-be-cleaned is 
blown off to the downstream side, reducing a chance for the splash to jump 
back into the ultrasonic rinsing nozzle. Moreover, according to the first 
preferred embodiment, swing of the rinsing mechanism changes the direction 
in which splash of the ultrasonic rinsing liquid is bounced off. To ensure 
the maximum ability of ultrasonic rinsing, the first preferred embodiment 
requires that the ultrasonic rinsing nozzle 10 injects the ultrasonic 
rinsing liquid F approximately perpendicularly to the surface of the 
substrate 1. In the first preferred embodiment, the rotation speed for 
rotating the substrate 1 is 500 rpm and the swing speed for swinging the 
rinsing mechanism is 200 mm/sec in the vicinity of the nozzles, for 
example. 
Meanwhile, the high-pressure rinsing nozzle 20 injects a high-pressure 
rinsing jet in an angled direction toward the downstream side of the 
ultrasonic rinsing liquid as shown in FIG. 3, which creates an advantage 
that a foreign matter which is removed by high-pressure rinsing is easily 
carried toward the downstream side. 
Further, since the apparatus according to the first preferred embodiment 
performs combined rinsing combining ultrasonic rinsing and high-pressure 
rinsing parallel in time within one apparatus, a cleaning time is short. 
Since this combined rinsing is combination of non-contact type rinsing 
methods, there is no damage to the substrate 1. 
Still further, since sufficient rinsing is realized by combination 
ultrasonic rinsing and high-pressure rinsing, it is not necessary to 
increase the jet pressure of high-pressure rinsing very much, and 
therefore, the high-pressure rinsing jet J does not damage the substrate. 
&lt;2-4. Swinging Scanning&gt; 
Next, rinsing utilizing swinging scanning will be described with reference 
to FIG. 5. In the first preferred embodiment, high-pressure rinsing is 
performed spot to spot and the ultrasonic rinsing line L is set narrower 
than the diameter width of the substrate 1. Hence, to clean the entire 
surface of the substrate 1, the substrate 1 is rotated within the 
horizontal plane while swinging the nozzles 10 and 20 which perform 
rinsing along a horizontal locus on the substrate 1. This swinging B, 
which is shown at the symbol B in FIG. 5, is carried out between a locus 
PT of the four corners of the substrate 1 resulting from rotation of the 
substrate 1 and the center of rotation CP. While FIG. 5 shows portions of 
three swing loci C, C.sub.1 and C.sub.2, the swing locus C in center is a 
locus which is traced by the swinging high-pressure rinsing spot P. The 
other swing loci C.sub.1 and C.sub.2 are loci which are traced by the both 
end points E.sub.1 and E.sub.2, respectively, of the ultrasonic rinsing 
line L. Since a distance between the high-pressure rinsing spot P and the 
center of revolution of the arm 52 (i.e., the column 51 in FIG. 1) is 
different from a distance between the both end points E.sub.1 and E.sub.2 
of the ultrasonic rinsing line L and the center of revolution of the arm 
52, the three oscillation loci C, C.sub.1 and C.sub.2 have different radii 
from each other. Moreover, in the first preferred embodiment, the 
oscillation locus C of the high-pressure rinsing spot P is set to pass 
immediately above the center of rotation CP of the substrate 1, so that 
all portions of the surface of the substrate 1 are cleaned by 
high-pressure rinsing. 
On the other hand, although the both end points E.sub.1 and E.sub.2 of the 
ultrasonic rinsing line L do not pass immediately above the center of 
rotation CP, this does not create any problem. This is because ultrasonic 
rinsing is performed line by line. As ultrasonic rinsing is performed line 
by line, the substrate is scanned by the ultrasonic rinsing line L over a 
section between the two oscillation loci C.sub.1 and C.sub.2. As far as 
the center of rotation CP is between the two oscillation loci C.sub.1 and 
C.sub.2, it is guaranteed that the respective portions of the substrate 1 
are subjected to ultrasonic rinsing. 
&lt;2-5. Relationship Between Swinging Scanning And Combined Rinsing&gt; 
As such positional relationships and swinging scanning are set and combined 
rinsing combining ultrasonic rinsing and high-pressure rinsing is 
performed on the substrate, scanning rinsing as described below is 
performed. 
First, an optional position on the surface of the substrate 1 is designated 
at A, as shown in FIG. 6. The position A is not virtually subjected to the 
rinsing effect when the rinsing nozzles 10 and 20 are at the solid-line 
positions in FIG. 6. 
As the rinsing nozzles 10 and 20 sway along an swing locus B, the position 
A crosses the ultrasonic rinsing line L while rotating in association with 
rotation of the substrate 1. Hence, the position A is subjected only to 
ultrasonic rinsing at this stage. 
As the rinsing nozzles 10 and 20 further sway up to a position which is 
denoted by the imaginary line of FIG. 6, the position A on the substrate 1 
passes across the high-pressure rinsing spot P and subsequently passes 
across the ultrasonic rinsing line L. At this stage, combined rinsing 
combining ultrasonic rinsing and high-pressure rinsing is performed on the 
position A. 
As the rinsing nozzles 10 and 20 further sway, the position A moves off 
both the high-pressure rinsing spot P and the ultrasonic rinsing line L. 
Although the rinsing nozzles 10 and 20 may sway only once to only one 
side, the first preferred embodiment requires repeated reciprocal swaying, 
in which case combined rinsing and ultrasonic rinsing are carried out 
repeatedly as the rinsing nozzles sway back and subsequently keep 
swinging. 
In this manner, the entire surface of the substrate 1 is subjected to 
combined rinsing. In the first preferred embodiment, when particularly 
noting the optional position A, there is a period in which the optional 
position A is rinsed only by ultrasonic rinsing but not by combined 
rinsing, this causes no problem. That is, since ultrasonic rinsing has an 
excellent liquid replaceability, even if there is a period in which 
ultrasonic rinsing alone is performed, there is no problem such as 
re-adhering of a removed foreign matter. Rather, when a foreign matter 
which can be removed only by ultrasonic rinsing is removed only by 
ultrasonic rinsing, it is possible to inject the high-pressure rinsing jet 
J only onto foreign matters which demand high-pressure rinsing, thereby 
further enhancing the rinsing effect. 
Further, swinging scanning as described above moves the high-pressure 
rinsing jet J in injected ultrasonic rinsing liquid, which in turn creates 
a bubbling-induced cavitation effect inside the rinsing liquid which is 
supplied onto the surface of the substrate. This further enhances the 
rinsing effect. 
&lt;2-6. Advantage Of Setting High-Pressure Rinsing Spot Shifted&gt; 
Next, with reference to FIG. 4, a description will be given on a reason for 
setting the high-pressure rinsing spot P shifted toward the farther one 
E.sub.1 of the end points E.sub.1 and E.sub.2 of the ultrasonic rinsing 
line L from the center of rotation CP of the substrate 1. FIG. 7 is a 
conceptual view showing swinging scanning for the structure shown in FIG. 
3, and FIG. 8 is a conceptual view showing swinging scanning for a case 
where conversely, the high-pressure rinsing spot P is set shifted toward 
the closer one E.sub.2 of the end points E.sub.1 and E.sub.2 of the 
ultrasonic rinsing line L to the center of rotation CP of the substrate 1. 
In either case, the high-pressure rinsing spot P is swung the locus PT of 
the four corners of the substrate 1 resulting from rotation of the 
substrate 1 and a point near the center of rotation CP. 
In the case shown in FIG. 7, in a condition (a) that the high-pressure 
rinsing spot P is over the locus PT, the ultrasonic rinsing nozzle 10 
injects the ultrasonic rinsing liquid toward the surface of the substrate. 
In a condition (b) as well that the high-pressure rinsing spot P is over 
the center of rotation CP, the ultrasonic rinsing nozzle 10 injects the 
ultrasonic rinsing liquid toward the surface of the substrate. Hence, 
wasteful use of the ultrasonic rinsing liquid is avoided in the entire 
range of an swinging amplitude .theta..sub.B. 
On the other hand, in the case shown in FIG. 8, in the condition (a) that 
the high-pressure rinsing spot P is over the locus PT, most of the rinsing 
liquid from the ultrasonic rinsing nozzle 10 is injected only outside the 
locus PT. This is wasteful use of the ultrasonic rinsing liquid. 
Thus, the arrangement according to the preferred embodiment shown in FIG. 3 
has an advantage that the rinsing liquid is not wasted. Conversely 
describing, when the same quantity of the rinsing liquid is used, the 
rinsing effect is better. 
&lt;2-7. Example Of First Preferred Embodiment&gt; 
Table 1 shows a result confirming the cleaning effect of the apparatus 
according to the first preferred embodiment shown in FIG. 1. For 
comparison, Table 1 shows a case (1) that only high-pressure jet rinsing 
is performed and a case (2) that only ultrasonic rinsing is performed. 
Conditions for experiments are as follows: 
Type Of Substrate 1 . . . a glass substrate for a liquid crystal display 
apparatus, with a chromium film formed at a surface; 
Plan Area Size Of Substrate 1 . . . 360 mm.times.465 mm; 
The Number Of Rotations Of Substrate 1 . . . 500 rpm; 
Jet Outlet Hole Size Of High-Pressure Rinsing Nozzle 20 . . . 0.1 mm .phi.; 
Supplied Jet Pressure To High-Pressure Rinsing Nozzle 20 . . . 15 
kgf/cm.sup.2 ; 
Ultrasonic Wave Power In Ultrasonic Rinsing Nozzle 10 . . . 110 W; 
Rinsing Time . . . 10 sec; and 
Measuring Method . . . counting the number of particles which are 1 .mu.m 
or larger before and after rinsing 
TABLE 1 
__________________________________________________________________________ 
THE NUMBER 
THE NUMBER OF TICLES OF RESIDUAL 
REMOVAL 
INITIAL TICLES AFTER 
AFTER ADHERING 
RATE OF 
RINSING METHOD SUBSTRATE A 
ADHERED(*) B 
RINSING C 
TICLES D 
RINSING E 
__________________________________________________________________________ 
ONLY HIGH-PRESSURE 
367 5829 450 83 98.5% 
JET RINSING 
ONLY ULTRASONIC 
301 5653 329 28 99.5% 
RINSING 
BOTH HIGH-PRESSURE JET 
431 4218 442 11 99.7% 
RINSING AND ULTRASONIC 
RINSING 
(PREFERRED EMBODIMENTS 
OF PRESENT INVENTION) 
__________________________________________________________________________ 
D = C - A 
E = [(B - D)/B] .times. 100 (%) 
(*)The number of particles in a condition that particles are additionally 
adhered to an initial substrate. 
As seen in Table 1, parallel use of a high-pressure jet and an ultrasonic 
wave according to the first preferred embodiment of the present invention 
enhances the effect of removing particles more than where only one of a 
high-pressure jet and an ultrasonic wave is used. 
Although a difference is about 0.2-1.2% in the removal rate, in the case of 
a glass substrate for a liquid crystal display apparatus, only a slight 
difference in the number of residual particles largely influence the yield 
of producing substrates after cleaning. Hence, the first preferred 
embodiment of the present invention produces a better result than when 
only one rinsing method is used. 
&lt;2-8. Modified Example Of First Preferred Embodiment&gt; 
The present invention is not limited to the first preferred embodiment 
described above, but the following various modified examples are possible. 
FIG. 9 represents a modified example where two high-pressure rinsing 
nozzles 20A and 20B are both used. In this case, one nozzle 20A of the two 
high-pressure rinsing nozzles is set so that a resulting rinsing spot 
P.sub.A is in the vicinity of the end point E.sub.1 of the ultrasonic 
rinsing line L, while the other high-pressure rinsing nozzle 20B is set so 
that a resulting rinsing spot P.sub.B is in the vicinity of the center of 
the ultrasonic rinsing line L. In this case, although it is sufficient to 
set an swinging amplitude .theta..sub.BC within a range the rinsing spot 
P.sub.B reaches the center of rotation CP, if the swinging amplitude is 
further widened, it is possible to subject the entire portion of the 
substrate to high-pressure rinsing twice only by means of performing 
swinging once (i.e., swaying one way). 
FIG. 10 shows an example of a structure in which the ultrasonic rinsing 
nozzle and the high-pressure rinsing nozzle are separated from each other. 
Of the nozzles, the length of the ultrasonic rinsing nozzle 10 is half the 
diagonal width of the substrate 1 or longer and the ultrasonic rinsing 
nozzle 10 does not swing while rinsing though nozzole 10 swings while 
rinsing in FIG. 5. An arm 71 which holds the ultrasonic rinsing nozzle 10 
is retractable as shown by the imaginary line, so that the substrate 1 is 
inserted and discharged when the arm retracts. On the other hand, the 
high-pressure rinsing nozzle 20 is held by an arm 72 which can translate 
in a direction T when driven by a translation scanning mechanism 73. In 
this apparatus, the ultrasonic rinsing liquid is injected as a curtain 
while rotating the substrate 1, and rinse-scanning is performed on the 
substrate 1 as the high-pressure rinsing nozzle 20 linearly moves. While 
integrating the ultrasonic rinsing nozzle 10 and the high-pressure rinsing 
nozzle 20 as shown in FIG. 1 enhances the economic use, the present 
invention is applicable to a structure where these nozzles are separated 
from each other as shown in FIG. 10. 
FIG. 11 shows an example using the high-pressure rinsing nozzle 20a which 
has a number of high-pressure rinsing liquid jet out holes JH which are 
arranged linearly. Although FIG. 11 does not show the positions of the 
high-pressure rinsing spots, the illustrated structure is similar to the 
first preferred embodiment of FIG. 1 in that the high-pressure rinsing 
spots are set close to the ultrasonic rinsing line L and on such a side so 
as to be scanned before the ultrasonic rinsing line L scans the rotating 
substrate. In this case, of the high-pressure rinsing spots of the number 
of the high-pressure rinsing liquid jet out holes JH, one high-pressure 
rinsing spot is preferably set to coincide with the center of rotation CP. 
With such an arrangement, the swing width of an high-pressure rinsing 
nozzle 20a may become very narrow by arranging the high-pressure rinsing 
liquid jet out holes JH at small intervals, or swinging may be omitted. 
The respective nozzles can retract by means of revolution as that shown at 
the symbol .theta..sub.11. 
FIG. 12 shows an example where high-pressure rinsing nozzle arrangements 
20a and 20b are disposed at the both ends of the ultrasonic rinsing nozzle 
10 whose length entirely covers the substrate. In this case as well, it is 
preferable that the high-pressure rinsing nozzle arrangements 20a and 20b 
are disposed on the side which is subjected to scanning earlier as the 
substrate rotates and that one of the high-pressure rinsing spots of the 
high-pressure rinsing liquid jet out holes JH forming these nozzle 
arrangements coincides with the center of rotation CP. Retracting of the 
nozzles may be realized by translation as that indicated at the symbol 
T.sub.12 in such an arrangement. 
Although it is preferable to perform high-pressure rinsing with a 
beam-shaped jet as in the first preferred embodiment described above, a 
slit may be used to perform high-pressure rinsing with a curtain-shaped 
jet. 
The present invention is applicable not only to rinsing of a glass 
substrate for a liquid crystal display apparatus, but to rinsing of 
various types of substrates, such as a semiconductor wafer, which are 
mainly for use in electric devices. 
3. Second Preferred Embodiment 
&lt;3-1. Mechanical Structure&gt; 
FIG. 13 is an essential perspective view of a substrate rinsing apparatus 
according to a second preferred embodiment of the present invention. This 
substrate cleaning apparatus 100 is structured for performing combined 
rinsing, i.e., ultrasonic rinsing and high-pressure rinsing parallel in 
time on the substrate 1 while translating the glass substrate 1 for a 
liquid crystal display apparatus and the combined cleaning mechanism 50 
relative to each other. First, the substrate which is to be cleaned is 
translated in a direction X in FIG. 13 by arranged rollers 60. While a 
motor M is disposed to realize translating, for convenience in 
illustration, FIG. 13 omits linkage between the motor M and the transport 
rollers. 
The combined cleaning mechanism 50 is disposed above a transportation path 
for the substrate 1. The combined cleaning mechanism 50 is constructed by 
arranging the high-pressure rinsing nozzles 20A and 20B near the both ends 
of the ultrasonic rinsing nozzle 10. Of the nozzles, the ultrasonic 
rinsing nozzle 10 has such an internal structure which will be described 
in detail later and is fixed by a stationary arm not shown externally to 
the substrate 1. The length of the ultrasonic rinsing nozzle 10 is equal 
to the Y-direction width of the substrate 1 or longer. The ultrasonic 
rinsing nozzle 10 injects rinsing liquid as a curtain from the slit onto 
the substrate 1. 
While FIGS. 2A and 2B shows the ultrasonic rinsing nozzle 10 according to 
the first preferred embodiment, as the apparatus according to the second 
preferred embodiment has the ultrasonic rinsing nozzle 10 of a similar 
shape, in the following, the ultrasonic rinsing nozzle 10 according to the 
second preferred embodiment will be described with reference to FIGS. 2A 
and 2B. 
FIG. 2A is a conceptual front view of the ultrasonic rinsing nozzle 10 in 
perspective, while FIG. 2B is a conceptual (partial) plan view of the 
ultrasonic rinsing nozzle 10 in perspective. In the ultrasonic rinsing 
nozzle 10, an ultrasonic wave is emitted from the ultrasonic wave 
oscillator 11 onto rinsing liquid F which is injected through the rinsing 
liquid inlet 12 and the rinsing liquid F is jetted out through the slit 13 
which is disposed beneath. 
A high frequency oscillating voltage is supplied to the ultrasonic wave 
oscillator 11. Preferably, the frequency of the supplied voltage is in the 
range of: 
0.8 MHz-2.0 MHz 
More preferably, the range is: 
1.2 MHz-1.8 MHz 
The rinsing liquid inlet 12 is linked to the resin tube 15 (See FIG. 13). 
The tube 15 is linked to the rinsing liquid supply part. 
On the other hand, each one of the high-pressure rinsing nozzles 20A and 
20B shown in FIG. 13 has an one-dimensional arrangement of needle-shaped 
nozzle tips 21 each having a jet out hole which is shaped as circle in 
cross section (Only some of the nozzle tips 21 are indicated at 21 in FIG. 
13.). The nozzle tips 21 jet out high-pressure jet rinsing liquid, which 
is supplied from the high-pressure rinsing liquid supply part through a 
resin tube 25, in the form close to a beam onto a surface of the substrate 
1. In each one of the high-pressure rinsing nozzles 20A and 20B, the 
length of the arrangement of the nozzle tips 21 is equal to the 
Y-direction width of the substrate 1 or longer. 
The pressure of the high-pressure rinsing liquid which is supplied to the 
high-pressure rinsing nozzles 20A and 20B is preferably in the range of: 
5 kg/cm.sup.2 -15 kg/cm.sup.2 
Further preferably, the pressure is in the range of: 
8 kg/cm.sup.2 -10 kg/cm.sup.2 
Further, each one of the high-pressure rinsing nozzles 20A and 20B is 
linked to an swing actuator 51 which uses a link mechanism or the like. 
The swing actuator 51 swings the high-pressure rinsing nozzles 20A and 20B 
at a predetermined swinging amplitude along the direction Y which is 
perpendicular to the translating direction X in which the substrate 1 
translates, namely, the direction of the arrangement of the nozzle tips 
21. The swinging amplitude is approximately equal to or larger than the 
intervals of the nozzle tips 21 in the direction Y. However, since it is 
possible to perform high-pressure rinsing entirely over the substrate 1 in 
the direction Y without oscillating the nozzles when the nozzle tips 21 
are arranged dense in the direction Y or when the high-pressure rinsing 
nozzles 20A and 20B are slit-shaped, the oscillation actuator 51 may be 
omitted and the high-pressure rinsing nozzles 20A and 20B may be fixed 
externally to the substrate 1. 
FIG. 14 is a view showing a positional relationship between the ultrasonic 
rinsing nozzle 10 and the high-pressure rinsing nozzles 20A and 20B within 
the apparatus 100. The ultrasonic rinsing nozzle 10 is disposed in such a 
manner that the ultrasonic rinsing liquid F is injected as a curtain 
toward the imaginary ultrasonic rinsing line L which is imaginarily 
defined at the surface of the substrate 1. The injection direction is 
approximately right angles with respect to the surface of the substrate 1. 
On the other hand, the high-pressure rinsing nozzles 20A and 20B are 
disposed at the both sides of the ultrasonic rinsing nozzle 10, so as to 
jet out a jet of the high-pressure rinsing liquid in an angled direction 
away from the injection direction in which the ultrasonic rinsing liquid F 
is injected from the ultrasonic rinsing nozzle 10. The axial line of this 
injection is toward the imaginary high-pressure rinsing spots P.sub.A and 
P.sub.B which are imaginarily defined at the surface of the substrate 1. 
FIG. 15 shows such a positional relationship as a plan view. As described 
with reference to FIG. 14, since the ultrasonic rinsing line L is 
immediately below the slit 13 of the ultrasonic rinsing nozzle 10, the 
ultrasonic rinsing line L is under the slit 13 in FIG. 15. Further, since 
each one of the high-pressure rinsing nozzles 20A and 20B has a number of 
the nozzle tips 21, the high-pressure rinsing spots P.sub.A are in an 
one-dimensional arrangement and so the high-pressure rinsing spots P.sub.B 
are. The high-pressure rinsing spots P.sub.A and P.sub.B are arranged 
parallel to and in the vicinity of the ultrasonic rinsing line L. 
&lt;3-2. Brief Description Of Operation&gt; 
Before describing a rinsing effect of the apparatus 100 in detail, a 
cleaning operation of the apparatus 100 will be generally described. 
First, the substrate 1 is transported from the left-upper direction in 
FIG. 13 to the direction X. Before a forward end of the substrate 1 comes 
close to the combined cleaning mechanism 50, the ultrasonic rinsing nozzle 
10 starts injecting the ultrasonic rinsing liquid and the high-pressure 
rinsing nozzles 20A and 20B start jetting out the high-pressure rinsing 
liquid. In addition, the swing actuator 51 starts swinging the 
high-pressure rinsing nozzles 20A and 20B with the same swinging amplitude 
and the same phase. 
The substrate 1, while transported in the direction X, is rinsed by 
combined rinsing combining ultrasonic rinsing and high-pressure rinsing. 
Combined rinsing is continued until a backward end of the substrate 1 
passes the combined cleaning mechanism 50, and subsequently, the substrate 
1 is transported further in the direction X and loaded into an apparatus 
which is disposed for the next step processing (such as a drying process). 
&lt;3-3. Details Of Combined Rinsing&gt; 
During combined rinsing according to the second preferred embodiment, as 
shown in FIG. 14, the jet J of the high-pressure rinsing is jetted out 
into the ultrasonic rinsing liquid F is injected from the ultrasonic 
rinsing nozzle 10. If an optional position within the substrate 1 is 
noted, the noted position is subjected to the high-pressure rinsing jet J 
from the high-pressure rinsing nozzle 20B, first, as the substrate is 
transported in the direction X. As there is a flow of the ultrasonic 
rinsing liquid F at the destination of the jet J, a foreign matter which 
is removed by high-pressure rinsing is washed away by the flow of the 
ultrasonic rinsing liquid F without adhering to the surface of the 
substrate 1 again. In addition, the high-pressure rinsing jet J moves 
within the ultrasonic rinsing liquid F as the high-pressure rinsing 
nozzles 20A and 20B are swung, and therefore, a bubbling-induced 
cavitation effect is created inside the rinsing liquid which is supplied 
onto the surface of the substrate. This further enhances the rinsing 
effect. 
As transportation in the direction X progresses, the optional position 
described above on the substrate 1 comes immediately below the ultrasonic 
rinsing nozzle 10, to be subjected to ultrasonic rinsing. A foreign matter 
which is removed by ultrasonic rinsing as well is carried away by the flow 
of the ultrasonic rinsing liquid F. 
As transportation in the direction X further progresses, the optional 
position described above on the substrate 1 is subjected to high-pressure 
rinsing by the high-pressure rinsing nozzle 20A. The effect of this second 
high-pressure rinsing is similar to that of the first high-pressure 
rinsing. The transportation speed for transporting the substrate in the 
direction X is slower than the oscillation speed for oscillating the 
high-pressure rinsing nozzles 20A and 20B. In the plan view in FIG. 15, 
even a portion within the surface of the substrate 1 which is located off 
the direction Y from the high-pressure rinsing spots P.sub.A and P.sub.B 
is subjected to high-pressure rinsing as the high-pressure rinsing nozzles 
20A and 20B oscillate. 
By the way, if the high-pressure rinsing jet J is jetted out toward the 
ultrasonic rinsing line L, the flow of the high-pressure rinsing jet J 
disturbs transmission of an ultrasonic wave upon the ultrasonic rinsing 
liquid F. 
Further, since the quantity of the ultrasonic rinsing liquid F is quite 
large at the position of the ultrasonic rinsing line L, disturbed by an 
excessive quantity of the ultrasonic rinsing liquid F, the high-pressure 
rinsing jet J may not reach at the surface of the substrate 1 at an 
excellent efficiency. 
The second preferred embodiment deals with this, as the high-pressure 
rinsing jets J are jetted out toward the high-pressure rinsing spots 
P.sub.A and P.sub.B which are set at positions which are in the vicinity 
of but a little away from the ultrasonic rinsing line L in the second 
preferred embodiment, and therefore, the quantity of the ultrasonic 
rinsing liquid F is appropriate at these positions and the efficiency of 
high-pressure rinsing is particularly high. 
On the other hand, the structure requiring the direction of the 
high-pressure rinsing jets J from the high-pressure rinsing nozzles 20A 
and 20B to be off the ultrasonic rinsing line L is related to an 
improvement in the effect of discharging a foreign matter which is removed 
by high-pressure rinsing. Taking the high-pressure rinsing nozzle 20B as 
an example, a foreign matter which is removed by high-pressure rinsing, 
due to the force of the high-pressure rinsing jet J, has a velocity 
component in the left-hand direction in FIG. 14 (i.e., the direction of 
the flow of the ultrasonic rinsing liquid F). Added to the flow of the 
ultrasonic rinsing liquid F, the velocity component aids discharging of a 
foreign matter outside the substrate 1. The effect of discharging a 
removed foreign matter is further enhanced in this manner. With respect to 
the high-pressure rinsing jet J from the other high-pressure rinsing 
nozzle 20A as well, this function is improved in a similar manner only 
with the directions reversed. 
FIG. 16 generalizes a relationship between the high-pressure rinsing jets J 
and the injection direction of injecting the ultrasonic rinsing liquid 
which is necessary to realize such a function. For the reason described 
above, the angles .theta..sub.A and .theta..sub.B of the high-pressure 
rinsing jets J from the high-pressure rinsing nozzles 20A and 20B with 
respect to the injection direction of injecting the ultrasonic rinsing 
liquid preferably have positive values. It is however possible to set 
.theta..sub.A =0 and .theta..sub.B =0 to ensure maximum use of the jet 
pressure if the high-pressure rinsing jets J are injected to the surface 
of the substrate 1 at right angles. Although this does not aid discharging 
of a foreign matter which is removed by high-pressure rinsing, with 
respect to the function that a removed foreign matter is not carried back 
toward the ultrasonic rinsing line L, this is as excellent as the case 
described above where the angles .theta..sub.A and .theta..sub.B have 
positive values. 
Further, even if the angles .theta..sub.A and .theta..sub.B have negative 
values, the effects of the present is not denied. However, it is desirable 
that the angles .theta..sub.A and .theta..sub.B have positive values as 
described above. When the angles .theta..sub.A and .theta..sub.B have 
positive values, the upper limit on the values of the angles .theta..sub.A 
and .theta..sub.B is determined in accordance with the minimum jet 
pressure which is necessary for removal of a foreign matter from the 
substrate 1. 
4. Third Preferred Embodiment 
&lt;4-1. Difference Between Third Preferred Embodiment And Second Preferred 
Embodiment&gt; 
FIG. 17 is an essential perspective view of a substrate cleaning apparatus 
200 according to a third preferred embodiment of the present invention. In 
the following, the apparatus 200, mainly its difference from the apparatus 
100 of FIG. 13, will be described. 
The apparatus 200 shown in FIG. 17 requires that in a combined cleaning 
mechanism 50a, the ultrasonic rinsing nozzle 10 is at an angle opposite to 
the direction X in which the substrate 1 is transported. The high-pressure 
rinsing nozzle 20 is disposed only on the opposite side to the direction X 
in which the substrate 1 is transported. Further, as shown in FIG. 18, the 
direction in which the ultrasonic rinsing nozzle 10 injects the ultrasonic 
rinsing liquid F is inclined at an angle opposite to the direction X for 
transporting the substrate 1, the high-pressure rinsing jet J from the 
high-pressure rinsing nozzle 20 is inclined at a similar angle, and the 
arrangement of the high-pressure rinsing spots P is set at such a position 
so as to scan the substrate 1 in the direction X before the ultrasonic 
rinsing line L scans the substrate 1. This is illustrated in the plan view 
showing the nozzles in FIG. 19. 
Referring to FIG. 18 again, with such a relationship as to arrangement, an 
optional position within the substrate 1 is subjected to high-pressure 
rinsing, first, and thereafter to ultrasonic rinsing. Although the present 
embodiment does not prohibit to reverse this order, the arrangement as 
that shown in FIG. 18 particularly prevents a foreign matter which is 
removed by the high-pressure rinsing jet J from returning near the 
ultrasonic rinsing line L, and also enhances the efficiency of ultrasonic 
rinsing. 
FIG. 20 should be referred to regarding an angular relationship between the 
respective types of rinsing. In FIG. 20, the angle .phi. is an angle of 
the injection direction of injecting the ultrasonic rinsing liquid with 
respect to the perpendicular line, and another angle .theta. is an angle 
of the high-pressure rinsing jet J with respect to the injection direction 
of injecting the ultrasonic rinsing liquid. The angle .phi. is set as a 
positive value. As a foreign matter which is removed by ultrasonic rinsing 
is carried toward the right-hand side in FIG. 20 as the substrate 1 is 
transported in the direction X, this creates an effect that the removed 
foreign matter does not return to the ultrasonic rinsing line L. Further, 
the angle .theta. is preferably zero or a positive value, as this helps a 
foreign matter which is removed by high-pressure rinsing flow in the 
opposite direction to the transportation direction X. The upper limit on a 
positive value of the angle .theta. is defined in accordance with a jet 
pressure which is necessary at the surface of the substrate 1. 
A general effect of combined rinsing combining ultrasonic rinsing and 
high-pressure rinsing in the apparatus 200 shown in FIG. 17 having such a 
structure is similar to that of the apparatus 100 of FIG. 13. Since the 
apparatus 200 shown in FIG. 17 is otherwise similar in structure to the 
apparatus 100 of FIG. 13, a redundant description will be simply omitted. 
&lt;4-2. Example Of Third Preferred Embodiment&gt; 
Table 2 shows a result confirming the rinsing effect of the apparatus 
according to the third preferred embodiment shown in FIG. 17. For 
comparison, Table 2 shows a case (1) that only high-pressure jet rinsing 
is performed and a case (2) that only ultrasonic rinsing is performed. 
Conditions for experiments are as follows: 
Type Of Substrate 1 . . . a glass substrate for a liquid crystal display 
apparatus, with a chromium film formed at a surface; 
Plan Area Size Of Substrate 1 . . . 360 mm.times.465 mm; 
Transportation Speed Of Substrate 1 . . . 1.2 m/min; 
Size And The Number Of Nozzle Tips 21 Of High-Pressure Rinsing Nozzle 20 . 
. . 18 Nozzle Tips Having Injection Diameter Of 0.1 mm .phi.; 
Supplied Jet Pressure To High-Pressure Rinsing Nozzle 20 . . . 15 
kgf/cm.sup.2 ; 
Ultrasonic Wave Power In Ultrasonic Rinsing Nozzle 10 . . . 500 W; 
Flow Rate Of Ultrasonic Rinsing Liquid In Ultrasonic Rinsing Nozzle 10 . . 
. 30 liters/min; 
Measuring Method . . . counting the number of particles which are 1 .mu.m 
or larger before and after rinsing 
TABLE 2 
__________________________________________________________________________ 
THE NUMBER 
THE NUMBER OF TICLES OF RESIDUAL 
REMOVAL 
INITIAL TICLES AFTER 
AFTER ADHERING 
RATE OF 
RINSING METHOD SUBSTRATE A 
ADHERED(*) B 
RINSING C 
TICLES D 
RINSING E 
__________________________________________________________________________ 
ONLY HIGH-PRESSURE 
302 5093 909 607 87.33% 
JET RINSING 
ONLY ULTRASONIC 
382 4603 795 413 90.22% 
RINSING 
BOTH HIGH-PRESSURE JET 
345 4543 660 315 92.50% 
RINSING AND ULTRASONIC 
RINSING 
(PREFERRED EMBODIMENTS 
OF PRESENT INVENTION) 
__________________________________________________________________________ 
D = C - A 
E = [(B - D)/B] .times. 100(%) 
(*)The number of particles in a condition that particles are additionally 
adhered to an initial substrate. 
As seen in Table 2, parallel use of a high-pressure jet and an ultrasonic 
wave according to the third preferred embodiment of the present invention 
enhances the effect of removing particles more than where only one of a 
high-pressure jet and an ultrasonic wave is used. 
Although a difference is about 2.3-5.2% in the removal rate, in the case of 
a glass substrate for a liquid crystal display apparatus, only a slight 
difference in the number of residual particles largely influence the yield 
of producing substrates after rinsing. Hence, the third preferred 
embodiment of the present invention produces a better result than when 
only one rinsing method is used. 
5. Fourth Preferred Embodiment 
FIG. 21 is an essential perspective view of a substrate cleaning apparatus 
300 according to a fourth preferred embodiment of the present invention, 
as it is viewed from below. The apparatus 300 is structured so as to rinse 
the back surface of the substrate 1. Mainly describing a difference from 
the second preferred embodiment, a combined cleaning mechanism 50b is 
disposed on the back surface side (i.e., downstream side) of the substrate 
1 in the apparatus 300. The positional relationship between the ultrasonic 
rinsing nozzle 10 and the high-pressure rinsing nozzle 20 is equal to that 
in the apparatus 200 according to the third preferred embodiment shown in 
FIG. 17 with the positions of the nozzles reversed in the vertical 
direction in a symmetrical manner with respect to the plane of the 
substrate 1. However, to prevent interference with the combined rinsing 
mechanism 50b, the rollers 60 for transporting the substrate are disposed, 
avoiding positions around the combined rinsing mechanism 50b. Like FIG. 
13, FIG. 21 only conceptually shows the motor M for driving the substrate 
1. 
The principles for rinsing in the apparatus 300 according to the fourth 
preferred embodiment are similar to those of the third preferred 
embodiment. However, since the ultrasonic rinsing liquid is injected up 
diagonally toward the back surface of the substrate 1, as shown in FIG. 
22, due to surface tension, after flowing a certain distance along the 
back surface of the substrate 1, the ultrasonic rinsing liquid F falls off 
below the substrate 1. Hence, the high-pressure rinsing jet J is jetted 
out within a range in which the ultrasonic rinsing liquid F still flows 
along the back surface of the substrate 1. 
Such back surface rinsing may be combined with surface rinsing of the 
second or the third preferred embodiment, thereby performing both-surface 
rinsing. Further, the substrate 1 may be transported in an upright posture 
and subjected to combined rinsing at the both surfaces. 
6. Modified Examples Of Second To Fourth Preferred Embodiments 
FIG. 23 is a plan view showing the positional relationship between the 
nozzles according to a modified example of the second to the fourth 
preferred embodiments. High-pressure rinsing nozzles 20C and 20D according 
to the modified example jet out the high-pressure rinsing jets J through 
slits 23. While the structures of the second to the fourth preferred 
embodiments where a beam-shaped jet is jetted out are preferable for 
guaranteeing the pressure of the high-pressure rinsing jets J during 
injecting without increasing the pressure of the high-pressure jets on the 
supply side very much, the high-pressure rinsing jets J like a curtain 
through the slits 23 as those shown in FIG. 23 may be used as well. In 
this case, it is not necessary to oscillate the high-pressure rinsing 
nozzles 20C and 20D. 
FIG. 24 is an essential plan view of other modified example. In FIG. 24, as 
an ultrasonic rinsing nozzle 10S and high-pressure rinsing nozzles 20E and 
20F, a combined cleaning mechanism 50c uses nozzles which are shorter than 
the width of the substrate 1 in the direction Y. In this case, the linkage 
member 52 and the arm 53 are linked to swing actuator 54, so that the 
nozzles 10S, 20E and 20F are swung while scanning in the direction Y over 
the entire width of the substrate 1. Internal structures and functions of 
the nozzles 10S, 20E and 20F are similar to those of the second preferred 
embodiment. Further, the high-pressure rinsing nozzles having one 
high-pressure rinsing liquid jet out hole may be swung over the entire 
width of the substrate 1. As oscillation takes a considerable time if the 
substrate 1 is large in these modified examples, it is preferable that a 
plurality of (desirably a number of) high-pressure rinsing liquid jet out 
holes are formed and the oscillation width is not very large. 
Although the second to the fourth preferred embodiments require to 
translate the substrate 1, the combined rinsing mechanism may be 
translated in the direction X or in the opposite direction. Alternatively, 
these two structures may be combined. Further, translation of the 
substrate and the combined rinsing mechanism relative to each other is not 
limited to one-side translation only in one direction but may be 
reciprocal translation. 
In addition to rinsing of a glass substrate for a liquid crystal display 
apparatus, the present invention is applicable to rinsing of various types 
of substrates, such as a semiconductor wafer, which are mainly for use in 
electric devices. 
While the invention has been described in detail, the foregoing description 
is in all aspects illustrative and not restrictive. It is understood that 
numerous other modifications and variations can be devised without 
departing from the scope of the invention.