Method of forming a resist pattern utilizing correlation between latent image height, resist pattern linewidth and surface modification layer width

• US 5,773,174 A
• Filed: 07/09/1997
• Issued: 06/30/1998
• Est. Priority Date: 11/14/1994
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Endo, Masayuki, Matsuo, Takahiro, Koizumi, Taichi
• Primary Examiner(s): Young, Christopher G.
• Application Number:
  US08/890,685
• Time in Patent Office: 356 Days
• Field of Search: 430/30, 430/315
• US Class Current: 430/30
• CPC Class Codes: G03F 7/038 Macromolecular compounds which are rendered insoluble or differentially wettable G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021
• CPC Class Codes: G03F 7/20 Exposure; Apparatus therefor photographic printing apparatus for making copies G03B27/00
• CPC Class Codes: G03F 7/265 Selective reaction with inorganic or organometallic reagents after image-wise exposure, e.g. silylation
• CPC Class Codes: G03F 7/30 Imagewise removal using liquid means
• CPC Class Codes: G03F 7/38 Treatment before imagewise removal, e.g. prebaking G03F7/265 takes precedence
• CPC Class Codes: G03F 7/70658 Electrical testing
• CPC Class Codes: G03F 7/70675 Latent image, i.e. measuring the image of the exposed resist prior to development

Abstract

A first correlation is obtained which is a correlation between latent image height produced after exposure on a resist layer, and resist pattern linewidth for a given length of develop time. Additionally, a second correlation is obtained which is a correlation between develop time for each exposure energy dose and resist pattern linewidth. The height of a latent image produced on an actually exposed resist layer is determined. From the first correlation, an estimated resist pattern linewidth, which is a resist pattern linewidth corresponding to a latent image height and to a given length of develop time, is found. From the second correlation, an estimated exposure energy dose, which is an exposure energy dose corresponding to a given length of develop time and to an estimated resist patten linewidth, is found. Additionally, also from the second correlation, develop time corresponding to a target resist pattern linewidth and to an estimated exposure energy dose is found, and according to the develop time found, a resist pattern is formed.

Claims

1. A method of forming a resist pattern comprising the steps of:

(a) forming a resist layer on a substrate;

(b) exposing said resist layer to light to form a predetermined pattern;

(c) performing a modification layer formation process to form a surface modification layer locally on said resist layer; and

(d) developing said pattern-exposed resist layer for resist pattern formation;

(1) determining a height of a latent image formed on said resist layer after said resist layer is exposed to said light;

(2) determining a relationship between the height of said latent image and an exposing parameter;

(3) determining a relationship between a surface modification layer-width and said exposing parameter;

(4) correlating the height of said latent image and surface modification layer-width based on relationships determined in steps (2) and (3) above;

(5) determining a first correlation between said height of said latent image and surface modification layer-width;

(6) determining a second correlation between the exposing parameter and surface modification layer-width;

(7) determining an actual latent-image height produced on an exposed resist layer;

(8) estimating from said first correlation a surface modification layer-width that corresponds to said determined actual latent-image height and to a given value of said exposing parameter;

(9) estimating from said second correlation an exposing parameter that corresponds to said given value of said exposing parameter and to said estimated resist pattern modification layer-width;

(10) determining from said second correlation, a value of said exposing parameter that corresponds to a target surface modification layer-width and to said estimated exposing parameter; and

(11) forming, based on said exposing parameter value found, a surface modification layer.

2. A method of forming a resist pattern according to claim 1,

wherein said exposing parameter is either one of a surface modification layer formation process time parameter or a surface modification layer formation process temperature parameter.

3. A method of forming a resist pattern according to claim 1 wherein said resist layer is composed of a resist which generates an acid when pattern-exposed to light, and wherein said surface modification layer is a metallic oxide layer which is formed such that an exposed portion of said resist layer is made to absorb moisture and then moisture and metallic alkoxide are applied onto a surface of said moisture-containing exposed portion for forming said metallic oxide layer on said exposed portion surface.

4. A method of forming a resist pattern according to claim 1 wherein said surface modification layer is a silylated layer which is formed on a surface of an unexposed portion of said resist pattern.

5. A method of forming a resist pattern according to claim 1 wherein said latent image height is determined using an atomic force microscope.

6. A method of forming a resist patten comprising the steps of:

(a) pre-obtaining a correlation between the width of a surface modification layer formed on a resist layer and the linewidth of a resist pattern resulting from developing said resist layer having thereon said surface modification layer;

(b) forming an actual resist layer on a substrate;

(c) exposing said actual resist layer to light to a predetermined pattern;

(d) forming an actual surface modification layer on said actual resist layer having said predetermined pattern;

(e) determining the width of said actual surface modification layer, and obtaining from said pre-found correlation an estimated linewidth which is a resist pattern-linewidth corresponding to said actual surface modification layer width determined;

(f) determining whether said estimated linewidth falls in a range of tolerance limits of a target linewidth, wherein if said estimated linewidth is found to fall in said range a develop process is performed on said actual resist layer to form a resist pattern, while on the other hand if said estimated linewidth is found not to fall in said range said actual resist layer is removed away from said substrate.

7. A method of forming a resist pattern according to claim 6 wherein said resist layer is composed of a resist which generates an acid when pattern-exposed to light, and wherein said surface modification layer is a metallic oxide layer which is formed such that an exposed portion of said resist layer is made to absorb moisture and then moisture and metallic alkoxide are applied onto a surface of said moisture-containing exposed portion for forming said metallic oxide layer on said exposed portion surface.

8. A method of forming a resist pattern according to claim 6 wherein said surface modification layer is a silylated layer which is formed on a surface of an unexposed portion of said resist pattern.

9. A method of forming a resist pattern according to claim 6 wherein the width of said surface modification layer is determined using an atomic force microscope.