EP0315375A2
Expired / Lapsed
EP
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Multilayer resist material and pattern forming method using the same
Assignee: Fujitsu Ltd
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Filing: 1988-10-28
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Granted: —
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Expires: 2008-10-28
Abstract
Abstract Multilayer resist materials contain a lowermost layer (15) having a high resistance to dry etching and made from polymers or copolymers of haloalkylated aromatic vinyl compound possessing a molecular weight and haloalkylation degree sufficient not to cause charging up therein during electron beam exposure. Pattern forming carried out using these materials yields fine resist patterns with a high resistance to dry etching and high accuracy and suitable for the production of semiconductor devices.
Inventors
- 👤 Shuzo Ohshio
- 👤 Koichi Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 00:47
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/094; G03F7/095; Y; Y10; Y10S; Y10S430/00; Y10S430/143
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
85 words
A multilayer resist material for use in an electron beam lithographic process which comprises, at least an outermost resist layer having a high sensitivity to electron beam exposure and a lowermost pattern-receiving layer having a high resistance to dry etching directly applied onto an underlying substrate to be dry etched, said pattern-receiving layer being made from a polymer or copolymer of a haloalkylated aromatic vinyl compound possessing a molecular weight and haloalkylation degree sufficient not to cause charging up therein during the electron beam exposure.
Claim 2
Dependent Claim
85 words
A multilayer resist material for use in an electron beam lithographic process which comprises, at least an outermost resist layer having a high sensitivity to electron beam exposure and a lowermost pattern-receiving layer having a high resistance to dry etching directly applied onto an underlying substrate to be dry etched, said pattern-receiving layer being made from a polymer or copolymer of a haloalkylated aromatic vinyl compound possessing a molecular weight and haloalkylation degree sufficient not to cause charging up therein during the electron beam exposure.
Claim 3
Dependent Claim
90 words
A multilayer resist material according to claim 1, in which said pattern-receiving layer is made from a copolymer having the following formula: wherein each Z represents atoms necessary to complete a substituted or unsubstituted aromatic ring, X represents a haloalkyl group, Y may or may not be present, and if present, represents a halogen, and m and n are integers representing polymerization degree, said copolymer having a molecular weight of 13000 or less and a haloalkylation degree, defined as percentage of m/(m + n) x 100, of 50% or more.
Claim 4
Dependent Claim
36 words
A multilayer resist material according to claim 2, in which said aromatic vinyl copolymer has the formula: wherein m and n each represents a polymerization degree necessary to provide a chloromethylation degree of 50% or more.
Claim 5
Dependent Claim
36 words
A multilayer resist material according to claim 2, in which said aromatic vinyl copolymer has the formula: wherein m and n each represents a polymerization degree necessary to provide a chloromethylation degree of 50% or more.
Claim 6
Dependent Claim
23 words
A multilayer resist material according to any preceding claim, in which said electron beam-sensitive resist layer is made from silylated or unsilylated polymethylsilsesquioxane.
Claim 7
Independent Claim
222 words
A method of forming a resist pattern on a substrate by using an electron beam lithographic process, which comprises the steps of: (a) applying onto a surface of a substrate to be dry etched a multilayer resist material which comprises, at least an outermost resist layer having a high sensitivity to electron beam exposure and a lowermost pattern-receiving layer having a high resistance to dry etching directly applied onto the underlying substrate, said pattern-receiving layer being made from a polymer or copolymer of a haloalkylated aromatic vinyl compound possessing a molecular weight and haloalkylation degree sufficient not to cause charging up therein during the electron beam exposure, (b) irradiating said multilayer resist material with a desired electron beam pattern to form a latent image corresponding to said irradiation pattern in said outermost resist layer, (c) developing said latent image to obtain a patterned distribution of said outermost resist layer, (d) when one or more interlayers exist between said outermost resist layer and said lowermost pattern-receiving layer, transferring said patterned distribution of said outermost resist layer to said one or more interlayers, and (e) dry etching said lowermost pattern-receiving layer through a mask which is provided by said patterned distribution of said outermost resist layer or lowermost interlayer, if any, to form thereby a patterned distribution of said pattern-receiving layer on said substrate.
Claim 8
Independent Claim
222 words
A method of forming a resist pattern on a substrate by using an electron beam lithographic process, which comprises the steps of: (a) applying onto a surface of a substrate to be dry etched a multilayer resist material which comprises, at least an outermost resist layer having a high sensitivity to electron beam exposure and a lowermost pattern-receiving layer having a high resistance to dry etching directly applied onto the underlying substrate, said pattern-receiving layer being made from a polymer or copolymer of a haloalkylated aromatic vinyl compound possessing a molecular weight and haloalkylation degree sufficient not to cause charging up therein during the electron beam exposure, (b) irradiating said multilayer resist material with a desired electron beam pattern to form a latent image corresponding to said irradiation pattern in said outermost resist layer, (c) developing said latent image to obtain a patterned distribution of said outermost resist layer, (d) when one or more interlayers exist between said outermost resist layer and said lowermost pattern-receiving layer, transferring said patterned distribution of said outermost resist layer to said one or more interlayers, and (e) dry etching said lowermost pattern-receiving layer through a mask which is provided by said patterned distribution of said outermost resist layer or lowermost interlayer, if any, to form thereby a patterned distribution of said pattern-receiving layer on said substrate.
Claim 9
Dependent Claim
90 words
A method according to claim 6, in which said multilayer resist material on said substrate is prepared by: (i) coating on a cleaned surface of said substrate a solution of said selected polymers or copolymers of haloalkylated aromatic vinyl compound to form said lowermost pattern-receiving layer, (ii) insolubilizing said pattern-receiving layer, (iii) if required, forming one or more interlayers on said insolubilized pattern-receiving layer, and (iv) coating on said insolubilized pattern-receiving layer, or said interlayers, a solution of said selected electron beam-sensitive resist material to form said outermost resist layer.
Claim 10
Dependent Claim
90 words
A method according to claim 7, in which said lowermost pattern-receiving layer is made from a copolymer having the following formula: wherein each Z represents atoms necessary to complete a substituted or unsubstituted aromatic ring, X represents a haloalkyl group, Y may or may not be present, and if present, represents a halogen, and m and n are integers representing a polymerization degree, said copolymer having a molecular weight of 13000 or less and a haloalkylation degree, defined as percentage of m/(m + n) x 100, of 50% or more.
Claim 11
Dependent Claim
34 words
A method according to claim 8, in which said aromatic vinyl copolymer has the formula: wherein m and n each represents a polymerization degree necessary to provide a chloromethylation degree of 50% or more.
Claim 12
Dependent Claim
34 words
A method according to claim 8, in which said aromatic vinyl copolymer has the formula: wherein m and n each represents a polymerization degree necessary to provide a chloromethylation degree of 50% or more.
Claim 13
Independent Claim
27 words
A method according to any one of claims 6 to 10, in which said lowermost pattern-receiving layer is insolubilized by heating through irradiation by far ultraviolet rays.
Claim 14
Independent Claim
24 words
A method according to any one of claims 6 to 11, in which said outermost resist layer is made from silylated or unsilylated polymethylsilsesquioxane.
Claim 15
Independent Claim
39 words
A method according to any one of claims 6 to 12, in which the developing in said step (c) is carried out by dipping the exposed multilayer resist material in a developing solution suitable for said outermost resist layer.
Claim 16
Independent Claim
50 words
A method according to any one of claims 6 to 13, in which a transfer of said patterned distribution of said outermost resist layer to said interlayers in said step (d) is carried out by dry etching said interlayers through said patterned outermost resist layer which acts as a mask.
References Cited (Backward Citations)
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