Photolithography process and materials

• US 10,394,126 B2
• Filed: 07/17/2015
• Issued: 08/27/2019
• Est. Priority Date: 07/17/2015
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Cheng, Ya-Ling, Chang, Ching-Yu, Wang, Chien-Wei, Chen, Yen-Hao
• Primary Examiner(s): Raymond, Brittany L
• Application Number:
  US14/802,756
• Publication Number:
  US 20170017158A1
• Time in Patent Office: 1,502 Days
• CPC Class Codes: G03F 7/32 Liquid compositions therefor, e.g. developers
• CPC Class Codes: G03F 7/322 Aqueous alkaline compositions
• CPC Class Codes: G03F 7/38 Treatment before imagewise removal, e.g. prebaking G03F7/265 takes precedence
• CPC Class Codes: G03F 7/405 Treatment with inorganic or organometallic reagents after imagewise removal

Abstract

One of the broader forms of the present disclosure relates to a method of making a semiconductor device. The method includes exposing a photoresist layer to a radiation source and applying a hardening agent to the photoresist layer. Therefore after applying the hardening agent a first portion of the photoresist layer has a higher glass transition temperature, higher mechanical strength, than a second portion of the photoresist layer.

Claims

1. A method comprising:

exposing a photoresist layer to a radiation source; and

developing the photoresist layer to form a patterned photoresist layer, wherein the developing includes applying a developing solution that comprises a hardening agent, and wherein the developing results in a first portion of the photoresist layer having a higher glass transition temperature (Tg) or a higher mechanical strength than a second portion of the photoresist layer.

2. The method of claim 1, wherein the first portion includes a top portion of the photoresist layer and the second portion includes a bottom portion of the photoresist layer positioned directly under the top portion of the photoresist layer.

3. The method of claim 2, wherein the hardening agent comprises a chemical structure as:

R_f-(L)_z

wherein R_f represents a spacer group L represents a link group, and z represents an integer, which is at least two,

wherein R_f is selected from the group consisting of aromatic carbon ring, straight or cyclic alkyl, alkoxyl, fluoroalkyl, fluoroalkoxyl, alkene, alkyne, hydroxyl, ketone, aldehyde, carbonate, carboxylic acid, ester, ether, amide, amine, imine, imide, azide, nitrate, nitrile, nitrite, and thiol spacer group, each having a chain of 1 to 12 carbon atoms, and

wherein L is selected from the group consisting of —

NH₂, —

OH, —

SH, —

COOH, —

COH, —

COOR, —

OCOR, —

COR, anhydride, epoxy group, R′

OR, R′

OOR, R′

OSOOR, and —

RX, wherein R′

is H, an unbranched or branched, cyclic or noncyclic, saturated or unsaturated alkyl or alkenyl or alkynyl group, and X is a halide.

4. The method of claim 2, the hardening agent is selected from the group consisting of anthracene-1, 8-dicarboxylic acid, di-ethanolamine, and acetone-1, 3-dicarboxylic acid, ethylenediamine, and NHR1R2, wherein R1 and R2 each includes H, alkyl, alkyne, alkyl, alkoxyl, fluoroalkyl, fluoroalkoxyl, alkene, alkyne, hydroxyl, ketone, aldehyde, carbonate, carboxylic acid, ester, ether, amide, amine, imine, imide, azide, nitrate, nitrile, or nitrite.

5. The method of claim 1, wherein the hardening agent comprises a chemical structure as:

R_f—

(P)_y

herein R_f represents a spacer group, P represents a polar group, and y represents an integer, which is at least two,

wherein R_f is selected from the group consisting of aromatic carbon ring, straight or cyclic alkyl, alkoxyl, fluoroalkyl, fluoroalkoxyl, alkene, alkyne, hydroxyl, ketone, aldehyde, carbonate, carboxylic acid, ester, ether, amide, amine, imine, imide, azide, nitrate, nitrile, nitrite, and thiol spacer group, each having a chain of 1 to 12 carbon atoms, and

wherein the P is selected from the group consisting of —

Cl, —

Br, —

I, —

NO₂, —

SO₃—

, —

H, —

CN, —

NCO, —

OCN, —

CO₂—

, —

OH, —

OR*, —

OC(O)CR*, —

SR, —

SO₂N(R*)₂, —

SO₂R*, —

SOR, —

OC(O)R*, —

C(O)OR*, —

C(O)R*, —

Si(OR*)₃, —

Si(R*)₃, and epoxyl groups, wherein R* is H, an unbranched or branched, cyclic or noncyclic saturated or unsaturated alkyl or alkenyl or alkynyl group.

6. A method comprising:

exposing a photoresist layer to a radiation source;

developing the photoresist layer to form a feature;

applying a hardening agent to the feature, wherein the hardening agent increases a glass transition temperature (Tg) or mechanical strength of the feature; and

applying a smoothing agent to the feature, wherein the smoothing agent reduces the glass transition temperature of the feature.

7. The method of claim 6, wherein the feature has a first cross-sectional profile shape prior to applying the smoothing agent and the hardening agent, and

wherein the feature has a second cross-sectional profile shape after applying the smoothing agent and the hardening agent, the second cross-sectional profile shape being different than the first cross-sectional profile shape.

8. The method of claim 7, wherein applying the hardening agent is performed prior to applying the smoothing agent to the feature.

9. The method of claim 7, wherein applying the hardening agent and applying the smoothing agent are performed together.

10. The method of claim 6, wherein after applying the hardening agent and the smoothing agent, a resultant Tg of the feature is decreased.

11. The method of claim 6, wherein the smoothing agent comprises a chemical structure as:

12. The method of claim 6, wherein the smoothing agent comprises a chemical structure as:

13. The method of claim 6, wherein the smoothing agent comprises a chemical structure as:

14. The method of claim 6, wherein the smoothing agent comprises a chemical structure as:

15. The method of claim 6, wherein the smoothing agent has a molecular weight ranging between about 150 Daltons and about 3000 Daltons.

16. A method, comprising:

exposing a photoresist layer to a radiation source;

applying a hardening agent and a developing solution to the photoresist layer, wherein the hardening agent increases mechanical strength of the photoresist layer;

developing the photoresist layer to form a feature; and

applying a smoothing agent to the feature wherein the smoothing agent reduces a glass transition temperature of the photoresist layer forming the feature.

17. The method of claim 16, wherein the hardening agent attaches to the photoresist layer by physical adsorption and/or covalent bond formation, and wherein the hardening agent is selected from the group consisting of di-ethanolamine, acetone-1,3-dicarboxylic acid, and anthracene-1,8-dicarboxylic acid.