Photomasks for photolithographic fine patterning

Claim 2

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.

Claim 3

The improved method of fine patterning in photolithography of claim 1, wherein said base plate of the photomask is a member selected from the group consisting of fused quartz and high silica glass.

Claim 4

The improved method of fine patterning in photolithography of claim 2, wherein the polymeric material covering the pattern-wise layer and the uncovered second portion of the base plate is selected from the group consisting of a rubbery copolymer of ethylene and vinyl acetate, polyvinyl acetate, polyvinyl chloride, polyethylene, epichlorohydrin rubber, polyisoprene, polyisobutylene, polychloroprene, chlorinated rubber, hydrochlorinated rubber, cyclized rubber, polyvinyl alkyl ethers, block copolymer of styrene and butadiene, gelatin, casein, cellulose, derivatives of cellulose, polymethyl isopropenyl ketone and polymethyl methacrylate.

Claim 5

The improved method of fine patterning in photolithography of claim 3, wherein the polymeric material is a rubber copolymer of ethylene and vinyl acetate.

Claim 6

The improved method of fine patterning in photolithography of claim 3, wherein the polymeric material is a block copolymer of styrene and butadiene.

Claim 7

The improved method of fine patterning in photolithography of claim 2, wherein the silicon-containing compound is a silane.

Claim 8

The improved method of fine patterning in photolithography of claim 1, wherein the silicon-containing compound is silicon tetrafluoride.

Claim 9

The improved method of fine patterning in photolithography of claim 1, wherein the direct contact between the photoresist material and the photomask is achieved by a process selected from one of the group consisting of vacuum suction, and nitrogen gas flowing.

Claim 10

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.

Claim 11

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.

Claim 12

The improved method of fine patterning in photolithography of claim 9, wherein said base plate of the photomask is a member selected from the group consisting of fused quartz and high silica glass.

Claim 13

The improved method of fine patterning in photolithography of claim 10, wherein the polymeric material covering the pattern-wise layer and the uncovered second portion of the base plate is selected from the group consisting of a rubbery copolymer of ethylene and vinyl acetate, polyvinyl acetate, polyvinyl chloride, polyethylene, epichlorohydrin rubber, polyisoprene, polyisobutylene, polychloroprene, chlorinated rubber, hydrochlorinated rubber, cyclized rubber, polyvinyl alkyl ethers, block copolymer of styrene and butadiene, gelatin, casein, cellulose, derivatives of cellulose, polymethyl isopropenyl ketone and polymethyl methacrylate.

Claim 14

The improved method of fine patterning in photolithography of claim 11, wherein the polymeric material is a rubber copolymer of ethylene and vinyl acetate.

Claim 15

The improved method of fine patterning in photolithography of claim 11, wherein the polymeric material is a block copolymer of styrene and butadiene.

Claim 16

The improved method of fine patterning in photolithography of claim 10, wherein the silicon-containing compound is a silane.

Claim 17

The improved method of fine patterning in photolithography of claim 10, wherein the silicon-containing compound is silicon tetrafluoride.

Claim 18

The improved of fine patterning in photolithography of claim 9, wherein the direct contact between the photoresist material and the photomask is achieved by a process selected from one of the group consisting of vacuum suction, and nitrogen gas flowing.

Claim 19

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.

Claim 20

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.

Claim 21

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.

Claim 22

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.