Photomasks for photolithographic fine patterning
AssigneeTokyo Ohka Kogyo Co., Ltd.
InventorHisashi Nakane
Life of this patent
Estimating the term…
Abstract
A photomask, used for the photolithographic fine patterning of a photoresist film in the preparation of semiconductors, is provided with a thin film of a polymeric material having resilient elasticity to cover the patterned masking layer and the surface of the substrate plate altogether so that very intimate contact is obtained between the photomask and the photoresist film contributing to a great increase in the resolving power in addition to the advantages of decreased stain and scratch formation on the surface of the photomask resulting in an increased productivity of semiconductor devices.
Claims18
An improved method of fine patterning in photolithography wherein the formation of a finely patterned layer of a photoresist material is formed on a substrate by providing a layer of photoresist material on the substrate, directly contacting the photoresist material with a photomask bearing a pattern of masking material, and irradiating the photoresist layer through the photomask, the improvement comprising substantially eliminating the gap space between the surface of the photoresist layer and the surface of the photomask when they are in direct contact, through the use of a photomask wherein;
- (a) a pattern-wise layer of the masking material is formed on one surface of a base plate which has a high transmission to ultraviolet light, thus covering a first portion of the base plate and leaving a second portion uncovered, said pattern-wise layer being substantially opaque to ultraviolet light,
- (b) providing a thin film of polymeric material in covering relationship with the pattern-wise layer and the uncovered second portion of said base plate, said film having a thickness of about 3-5 microns as measured from the surface of the base plate and being characterized as having resilient elasticity and;
- wherein the surface of the thin film of the polymeric material of the photomask has been subjected to exposure to a plasma atmosphere of a silicon-containing compound.
An improved method of fine patterning in photolithography wherein the formation of a finely patterned layer of a photoresist material is formed on a substrate by providing a layer of photoresist material on a substrate, said photoresist material having a rugged surface texture, directly contacting the photoresist material with a photomask bearing a pattern of masking material, and irradiating the photoresist layer through the photomask, the improvement comprising substantially eliminating the gap space between the surface of the photoresist layer and the surface of the photomask when they are in direct contact, through the use of a photomask wherein;
- (a) a pattern-wise layer of the masking material is formed on one surface of a base plate which has a high transmission to ultraviolet light, thus covering a first portion of the base plate and leaving a second portion uncovered, said pattern-wise layer being substantially opaque to ultraviolet light,
- (b) providing a thin film of polymeric material in covering relationship with the pattern-wise layer and the uncovered second portion of said substrate, said film having a thickness of about 3-5 microns as measured from the surface of the substrate and being characterized as having resilient elasticity and;
- wherein the surface of the thin film of the polymeric material of the photomask has been subjected to exposure to a plasma atmosphere of a silicon-containing compound.
An improved method of fine patterning in photolithography wherein the formation of a finely patterned layer of a photoresist material is formed on a substrate by providing a layer of photoresist material on the substrate, directly contacting the photoresist material with a photomask bearing a pattern of masking material, and irradiating the photoresist layer through the photomask, the improvement comprising substantially eliminating the gap space between the surface of the photoresist layer and the surface of the photomask when they are in direct contact, through the use of a photomask wherein;
- (a) a pattern-wise layer of the masking material is formed on one surface of a base plate which has a high transmission to ultraviolet light, thus covering a first portion of the base plate and leaving a second portion uncovered, said pattern-wise layer being substantially opaque to ultraviolet light,
- (b) providing a thin film of a polymeric material in a covering relationship with the pattern-wise layer and the uncovered second portion of the said base plate, said film having a thickness of about 3-5 microns as measured from the surface of the base plate and being characterized as having resilient elasticity and;
- (c) wherein the surface of the thin film of the polymeric material of the photomask has been subjected to exposure to a plasma atmosphere of a gas of a material chosen from the group consisting of a silane and silicon tetrafluoride.
An improved method of fine patterning in photolithography wherein the formation of a finely patterned layer of a photoresist material is formed on a substrate by providing a layer of photoresist material on a substrate, said photoresist material having a rugged surface texture, directly contacting the photoresist material with a photomask bearing a pattern of masking material, and irradiating the photoresist layer through the photomask, the improvement comprising substantially eliminating the gap space between the surface of the photoresist layer and the surface of the photomask when they are in direct contact, through the use of a photomask wherein;
- (a) a pattern-wise layer of the masking maerial is formed on one surface of a base plate which has a high transmission to ultraviolet light, thus covering a first portion of the base plate and leaving a second portion uncovered, said pattern-wise layer being substantially opaque to ultraviolet light,
- (b) providing a thin film of a polymeric material in a covering relationship with the pattern-wise layer and the uncovered second portion of said base plate, said film having a thickness of about 3-5 microns as measured from the surface of the base plate and being characterized as having resilient elasticity and;
- wherein the surface of the thin film of the polymeric material of the photomask has been subjected to exposure to a plasma atmosphere of a gas of a material chosen from the group consisting of a silane and silicon tetrafluoride.
Dependencies are inferred from the claim text.