Methods of forming patterns for semiconductor device structures

Patent metadata

Field	Value
Publication number	US-9213239-B2
Application number	US-201313746543-A
Country	US
Kind code	B2
Filing date	Jan 22, 2013
Priority date	Jan 22, 2013
Publication date	Dec 15, 2015
Grant date	Dec 15, 2015

Abstract

Methods of forming a pattern in a semiconductor device structure include deprotecting an outer portion of a first photosensitive resist material, forming a second photosensitive resist material, exposing portions of the first and second photosensitive resist materials to radiation, and removing the deprotected outer portion of the first photosensitive resist material and the exposed portions of the first and second photosensitive resist materials. Additional methods include forming a first resist material over a substrate to include a first portion and a relatively thicker second portion, deprotecting substantially the entire first portion and an outer portion of the second portion while leaving an inner portion of the second portion protected, and forming a second resist material over the substrate. A portion of the second resist material is exposed to radiation, and deprotected and exposed portions of the first and second resist materials are removed.

First claim

What is claimed is:

1. A method of forming a pattern in a semiconductor device structure, the method comprising:
forming a first photosensitive resist material over a substrate;
exposing the first photosensitive resist material to radiation through a mask;
developing the first photosensitive resist material to form trenches in the first photosensitive resist material and expose the substrate between adjacent portions of the first photosensitive resist material;
filling the trenches between the adjacent portions of the first photosensitive resist material with a chemically active species to form a chemically modified outer portion of each of the adjacent portions of the first photosensitive resist material while an inner portion of each of the adjacent portions of the first photosensitive resist material remains chemically unmodified;
forming a second photosensitive resist material over the chemically modified outer portion of each of the adjacent portions of the first photosensitive resist material;
exposing portions of the second photosensitive resist material to another radiation;
exposing the inner portion of at least some of the adjacent portions of the first photosensitive resist material to the another radiation through the second photosensitive resist material and the chemically modified outer portion; and
removing the chemically modified outer portion of each of the adjacent portions of the first photosensitive resist material, the exposed inner portion of each of the adjacent portions of the first photosensitive resist material, and the exposed portions of the second photosensitive resist material to form a pattern in the first photosensitive resist material and the second photosensitive resist material.

2. The method of claim 1 , wherein the filling the trenches between the adjacent portions of the first photosensitive resist material with a chemically active species comprises:
disposing an acid solution in contact with the first photosensitive resist material; and
diffusing acid from the acid solution into the first photosensitive resist material.

3. The method of claim 2 , wherein the diffusing the acid from the acid solution into the first photosensitive resist material comprises subjecting the acid solution and the first photosensitive resist material to a temperature in the range of from about 80° C. to about 130° C.

4. The method of claim 2 , wherein the diffusing the acid from the acid solution into the first photosensitive resist material comprises subjecting the acid solution and the first photosensitive resist material to a temperature for between about 0.5 minute and about 3 minutes.

5. The method of claim 2 , wherein the disposing the acid solution comprises disposing one or more of a triflic acid and a perfluorobutanesulfonic acid.

6. The method of claim 1 , wherein at least one of the exposed inner portions of the first photosensitive resist material and at least one of the exposed portions of the second photosensitive resist material are located in an array region of the semiconductor device structure.

7. The method of claim 1 , wherein the developing the first photosensitive resist material to form the trenches in the first photosensitive resist material comprises forming the trenches in the first photosensitive resist material selected from the group consisting of a methacrylate material, an acrylate material, a polyhydroxystyrene material with an tert-butoxycarbonly (tBOC) protection group, a poly[4-(2-hydroxyhexafluoroisopropyl)styrene] material with a tBOC protection group, a poly(4-tert-butoxycarbonyloxystyrene) with a tBOC protection group, a poly(4-t-butoxycarbonyloxystyrene-sulfone) material, and a polyether material based on alkoxypyrimidine units.

8. The method of claim 1 , wherein the forming the second photosensitive resist material over the chemically modified outer portion of each of the adjacent portions of the first photosensitive material comprises forming the second photosensitive resist material selected from the group consisting of a methacrylate material, a polyhydroxystyrene material, a poly(butene-1-sulfone) material, an acrylate material, and a copolymer of chloromethacrylate and methylstyrene.

9. The method of claim 1 , further comprising selecting the second photosensitive resist material to be soluble in a different solvent than the first photosensitive resist material.

10. The method of claim 1 , further comprising selecting the second photosensitive resist material to be sensitive to a wavelength of radiation to which the first photosensitive resist material is sensitive.

11. The method of claim 1 , further comprising selecting the second photosensitive resist material to be formulated for development in a developer solution in which the first photosensitive resist material is formulated for development.

12. The method of claim 1 , further comprising removing a portion of the substrate through the pattern in the first photosensitive resist material and the second photosensitive resist material.

13. The method of claim 12 , wherein the removing the portion of the substrate through the pattern comprises removing portions of a metal material overlying an active area of the substrate to form a plurality of conductive features from the metal material.

14. A method of forming a pattern in a semiconductor device structure, the method comprising:
forming a first resist material over a substrate to include at least one first portion and at least one second portion adjacent the at least one first portion, the at least one first portion being relatively thinner than the at least one second portion;
diffusing a chemically active species into substantially all of the at least one first portion of the first resist material to form a chemically modified at least one first portion of the first resist material;
diffusing the chemically active species into an outer portion of the at least one second portion of the first resist material to form a chemically modified outer portion of the at least one second portion of the first resist material while leaving an inner portion of the at least one second portion of the first resist material chemically unmodified;
forming a second resist material adjacent to the chemically modified at least one first portion of the first resist material and the chemically modified outer portion of the at least one second portion of the first resist material;
exposing at least one portion of the second resist material to radiation; and
removing the chemically modified at least one first portion of the first resist material, the chemically modified outer portion of the at least one second portion of the first resist material, and the exposed at least one portion of the second resist material.

15. The method of claim 14 , further comprising:
exposing the chemically unmodified inner portion of the at least one second portion of the first resist material to the radiation; and
removing the exposed chemically unmodified inner portion of the at least one second portion of the first resist material.

16. The method of claim 14 , wherein the removing the chemically modified at least one first portion of the first resist material, the chemically modified outer portion of the at least one second portion of the first resist material, and the exposed at least one portion of the second resist material comprises developing the chemically modified at least one first portion of the first resist material, the chemically modified outer portion of the at least one second portion of the first resist material, and the exposed at least one portion

Assignees

• Light Scott
• He Yuan
• Many Michael A
• Hyatt Michael
• Micron Technology Inc

Inventors

• Light Scott
• He Yuan
• Many Michael A
• Hyatt Michael

Classifications

• H10P76/204

  of organic photoresist masks · CPC title

• H10P50/71

  using masks for conductive or resistive materials · CPC title

• G03F7/2022 Primary

  Multi-step exposure, e.g. hybrid; backside exposure; blanket exposure, e.g. for image reversal; edge exposure, e.g. for edge bead removal; corrective exposure · CPC title

• G03F7/095

  having more than one photosensitive layer (G03F7/075 takes precedence) · CPC title

• G03F7/325

  Non-aqueous compositions · CPC title