Source: http://www.google.com/patents/US5266424?dq=7143430
Timestamp: 2017-12-18 15:43:20
Document Index: 681768078

Matched Legal Cases: ['art 51', 'art 50', 'art 7', 'art 7', 'art 7', 'art 7', 'art 24', 'art 25', 'art 25']

Patent US5266424 - Method of forming pattern and method of manufacturing photomask using such ... - Google Patents
The present invention is mainly directed to provision of a method of producing a highly precise resist pattern, even when a high energy beam is used. Resist containing a base resin including a hydroxyl group, an acid generating agent irradiated with radiation for generating sulfonic acid, and a cross...http://www.google.com/patents/US5266424?utm_source=gb-gplus-sharePatent US5266424 - Method of forming pattern and method of manufacturing photomask using such method
Publication number US5266424 A
Application number US 07/849,602
Publication number 07849602, 849602, US 5266424 A, US 5266424A, US-A-5266424, US5266424 A, US5266424A
Inventors Takeshi Fujino, Yaichiro Watakabe
Patent Citations (3), Non-Patent Citations (8), Referenced by (21), Classifications (20), Legal Events (5)
US 5266424 A
applying onto a substrate a resist containing a base resin including a hydroxyl group, an acid generating agent for generating a sulfonic acid when irradiated with radiation, and a cross linking agent for reacting with the hydroxyl group of the base resin by the catalytic action of the proton of the sulfonic acid to thereby cross link said base resin;
selectively irradiating the resist with radiation, thereby dividing the resist into an exposed part and a non-exposed part and generating the sulfonic acid in the resist at the exposed part;
heating the resist to a first temperature so as to cause the hydroxyl group of the base resin to react with the cross linking agent by the catalytic action of the proton of the sulfonic acid, thereby cross linking the exposed part of the resist;
prior to dry developing the resist, selectively silylating the surface of the non-exposed part of the resist by heating the resist to a second temperature and exposing the resist in an atmosphere of a silylating agent; and
dry-developing the resist with oxygen plasma to remove the exposed part of the resist and simultaneously convert a silylated layer formed on the surface of the non-exposed part of the resist to silicon dioxide, thereby forming a positive type resist pattern.
2. A method as recited in claim 1, wherein said acid generating agent includes triphenyl sulfonium triflate.
8. A method as recited in claim 1, wherein said first temperature is in the range between 50° and 150° C.
said second temperature is in the range between 40° and 140° C.
10. A method as recited in claim 1, wherein said base resin includes novolac resin.
said radiation includes an electron beam of energy in the range between 1 and 100 keV.
12. A method as recited in claim 1, wherein said silylating agent includes 1, 1, 3, 3-tetramethyldisilazane.
forming a metal layer on a glass substrate;
applying onto the metal layer a resist containing a base resin including a hydroxyl group, an acid generating agent for generating a sulfonic acid when irradiated with radiation, and a cross linking agent for reacting with the hydroxyl group of the base resin by the catalytic action of the proton of the sulfonic acid to thereby cross link the base resin;
heating the resist to a first temperature so as to cross link the exposed part of the resist by causing the reaction of the hydroxyl group of the base resin and the cross linking agent in the presence of the proton of the sulfonic acid as the catalyst;
prior to dry developing the resist, selectively silylating the surface of the non-exposed part of the resist by heating the resist to a second temperature and exposing the resist in an atmosphere of a silylating agent;
dry-developing said resist with oxygen plasma to remove the exposed part of the resist and simultaneously convert a silylated layer formed on the surface of the non-exposed part of the resist to silicon dioxide, thereby forming a positive type resist pattern;
selectively etching the metal layer using the positive type resist pattern as a mask; and
removing the positive type resist pattern.
14. A method as recited in claim 13, wherein said radiation includes an electron beam.
17. A method as recited in claim 16, wherein
said melamine derivative includes hexamethylol-melamine-hexamethylether.
18. A method as recited in claim 13, wherein
said first temperature is in the range between 50° and 150° C.
Referring to FIG. 10(a), a film 2 is formed on a substrate 1. A dry development resist 3 is formed on film 2. Dry development resist 3 is, for example, a PLASMASK® resist manufactured by JAPAN SYNTHETIC RUBBER Co. Ltd. The composition of PLASMASK® is not known in detail, but the resist contains novolac resin shown in FIG. 11(a) and quinondiazide shown in FIG. 11(b) form the principle constituents.
Referring to FIG. 10(c), while heating substrate 1 to 120°-200° C., the mixed gas of a hexamethyldisilazane (HMDS) gas and a nitrogen gas is blown onto substrate 1. This treatment is called silylating process. The mixed gas of the HMDS gas and nitrogen gas is produced by bubbling nitrogen into liquid HMDS.
Referring to FIG. 1(a), resist 7 is applied on a substrate 1. Resist 7 contains base resin including a hydroxyl group, an acid generating agent which generates sulfonic acid upon irradiation, and a cross linking agent which reacts with the hydroxyl group of the base resin by the catalytic action of the proton of the sulfonic acid and thereby cross links base resins. More specifically, novolac resin shown in FIG. 2(a) is used for the base resin, hexamethylol-melamine-hexamethylether shown in FIG. 2(b) is used for the cross linking agent, and triphenyl sulfonium triflate shown in FIG. 2(c) is used for the acid generating agent. The weight ratio of the above-stated three components is base resin:cross linking agent:acid generating agent=100:20:10. The ratio of mixing is preferably: cross linking agent 5-30 weight %, acid generating agent 3-15 weight % relative to base resin 100. The solution of resist is made by dissolving these three components into methyl cellosolve acetate 2. The solution of the resist is filtered and applied onto substrate 1 by means of spin coating. The substrate is then prebaked for one minute at a temperature of 85° C., thereby forming a uniform resist film 7 having a thickness of 1.2 μm on substrate 1. The thickness of resist film 7 is preferably in the range of 0.5 and 2 μ m.
Referring to FIG. 1(b), electron beam of energy 20KeV is selectively emitted upon resist film 7 by exposure in the range between 1 and 10×10-6 C/cm2, thereby dividing resist 7 into the exposed part 51 and the non exposed part 50. At the exposed part of resist film 7, triphenyl sulfonium triflate decomposes as in the reaction formula shown in FIG. 3 and trifluoromethane sulfonic acid which is a strong acid is generated.
Referring to FIG. 1(c), baking after the exposure is conducted for two minutes at a temperature in the range between 50° and 150° C., preferably in the range between 100° and 130° C. A description will be provided on how cross linking goes at the exposed part of base resin 7 at the time of baking in conjunction with FIG. 4.
Substrate 7 which was subjected to heat-treatment as shown in FIG. 1(c) is placed on heating means 12. Substrate 7 is heated by heating means 12 to a temperature identical to the temperature of baking after the exposure or lower, for example, a temperature in the range between 40° and 140° C., preferably between 100° and 130° C. Nitrogen gas is introduced into HMDS tank 18 via nitrogen gas conduit 19. Nitrogen gas is bubbled into the HMDS liquid 13. The bubbling of nitrogen gas allows the mixed gas of HMDS gas and nitrogen gas to be introduced into vacuum chamber 15 through HMDS conduit 17. The HMDS gas introduced into vacuum chamber 15 silylates the resist. This silylating reaction take place for 2-10 minutes.
More specifically, the glass transition temperature of the resin is raised by the cross linking at the cross linked part 7a. The resin therefore does not loosen at the cross linked part 7a even when resist 7 is heated to a temperature in the range between 100° and 130° C. as described above. As the resin does not loosen the HMDS can not permeate therein.
Meanwhile at the non-cross linked part 7b, with no cross linking taking place, the resin loosens when heated to a temperature in the range between 100° and 130° C., facilitating the HMDS to enter. Therefore, silylating layer 8 is formed only at the non-cross linked part 7b.
Referring to FIG. 9(c), resist 23 is baked to a temperature in the range between 50° and 150° C. This baking allows the exposed part of resist 23 to cross link, separating the cross linked part 24 and non-cross linked part 25.
Referring to FIG. 9(d), resist 23 is exposed in an atmosphere of HMDS at a temperature in the range between 40° and 140° C., and the surface of the non-cross linked part 25 of resist 23 is thus selectively silylated, forming a silylated layer 26.
Although in the above-stated embodiment, the resin shown in FIG. 2(a) is used for the novolac resin, a resin having the general formula shown in FIG. 2(d) may be used. Resin can be preferably used such as m-cresol • p-cresol • formaldehyde • novolac resin, phenol • m-cresol • formaldehyde • novolac resin, and m-cresol • formaldehyde • novolac resin.
1 "Desire" (Diffusion Enhanced Silylating Resist), Technical Report, pp. 48-50, 1988.
2 "Positive Resist Image by Dry Etching: New Dry Developed Positive Working System for Electron Beam and Deep Ultraviolet Lithography", J. Vac. Sci. Technol, vol. B7(6), pp. 1782-1786, Nov./Dec. 1989.
3 "Silylated Acid Hardened Resist [SAHR] Technology: Positive, Dry Developable Deep UV Resists", SPIE Dry Process Symposium, James W. Thackeray, et al., pp. 1-15, 1989.
4 "Silylation and Dry Development of Three Component Resists for Half-Micron Lithography", SPIE Advances in Resists Technology and Processing, Thierry G. Vachette, et al., pp. 1-15, Mar. 1990.
5 * Desire (Diffusion Enhanced Silylating Resist), Technical Report, pp. 48 50, 1988.
6 * Positive Resist Image by Dry Etching: New Dry Developed Positive Working System for Electron Beam and Deep Ultraviolet Lithography , J. Vac. Sci. Technol, vol. B7(6), pp. 1782 1786, Nov./Dec. 1989.
7 * Silylated Acid Hardened Resist SAHR Technology: Positive, Dry Developable Deep UV Resists , SPIE Dry Process Symposium, James W. Thackeray, et al., pp. 1 15, 1989.
8 * Silylation and Dry Development of Three Component Resists for Half Micron Lithography , SPIE Advances in Resists Technology and Processing, Thierry G. Vachette, et al., pp. 1 15, Mar. 1990.
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US6746827 * Apr 29, 2002 Jun 8, 2004 Infineon Technologies Ag Process for structuring a photoresist layer
US6887653 * Apr 29, 2002 May 3, 2005 Infineon Technologies Ag Method for structuring a photoresist layer
US20080261389 * Dec 21, 2007 Oct 23, 2008 Hynix Semiconductor Inc. Method of forming micro pattern of semiconductor device
CN101290867B Feb 19, 2008 Jun 16, 2010 海力士半导体有限公司 Method of forming micro pattern of semiconductor device
U.S. Classification 430/5, 430/296, 430/329, 430/330, 430/270.1
International Classification G03F1/76, G03F1/78, G03F7/004, H01L21/027, G03F7/36, G03F7/039, H01L21/30, G03F7/38, G03F7/26
Cooperative Classification G03F7/36, G03F7/039, G03F7/265
European Classification G03F7/36, G03F7/039, G03F7/26D
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:FUJINO, TAKESHI;WATAKABE, YAICHIRO;REEL/FRAME:006144/0839