Photoresist with top-coating photo-decomposable base for photolithography

Patent metadata

Field	Value
Publication number	US-9645499-B2
Application number	US-201514833029-A
Country	US
Kind code	B2
Filing date	Aug 21, 2015
Priority date	Aug 28, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A lithographic method includes forming a photoresist layer on a target layer, forming a photo-decomposable base (PDB) layer on the photo resist layer, performing an exposure operation using a mask, and performing a negative development treatment to form a patterned photoresist layer on the target layer. In some cases, the photo-decomposable base layer includes a self-generating top coating photo-decomposable base (TC-PDB) layer. The method can also include forming a top surface water-resistant coating in separate coating process. In some embodiments, a top surface water-resistant coating is self-generated during a photoresist coating process.

First claim

What is claimed is:

1. A lithographic method, comprising:
forming a photoresist layer on a target layer;
forming a photo-decomposable base (PDB) layer on the photo resist layer;
performing an exposure operation using a mask exposing a region of the PDB layer so that a top surface of an exposed region of the PDB layer has a base concentration higher than a base of the exposed region of the PDB layer; and
performing a negative development process to form a patterned photoresist layer on the target layer.

2. The method of claim 1 , wherein the photo-decomposable base layer comprises a self-generating top coating photo-decomposable base (TC-PDB) layer.

3. The method of claim 1 , further comprising forming a top surface water-resistant coating in a separate coating process.

4. The method of claim 1 , wherein a top surface water-resistant coating is self-generated during a photoresist coating process.

5. The method of claim 1 , wherein the photo-decomposable base layer comprises a fluorinated monocarboxylate cation photo-decomposable base or a fluorinated dicarboxylate cation photo-decomposable base.

6. The method of claim 1 , wherein forming a photo-decomposable base (PDB) layer comprises a coating method.

7. The method of claim 1 , wherein forming a photoresist layer comprises coating a positive photoresist layer, the positive photoresist layer including photo-acid generator (PAG), resist additives, and solvents.

8. The method of claim 7 , wherein the photo acid generator can include onium salts, aromatic diazonium salts, sulfonium salts, diaryliodonium salts, dodecane sulfonate of N-hydroxy-naphthalimide, and one or more of sulfonic acid esters in N-hydroxyamides.

9. The method of claim 1 , further comprising forming a bottom antireflective coating layer before forming the photoresist layer.

10. A lithographic method, comprising:
forming a composite layer on a target layer, the composite layer including a photo-decomposable base (PDB) layer over a photo resist layer;
performing an exposure operation using a mask exposing a region of the PDB layer so that a top surface of an exposed region of the PDB layer has a base concentration higher than a base of the exposed region of the PDB layer; and
performing a negative development treatment to form a patterned photoresist layer on the target layer.

11. The method of claim 10 , wherein forming a composite layer on a target layer comprises:
forming a photoresist layer on the target layer; and
forming a photo-decomposable base (PDB) layer over the photo resist layer.

12. The method of claim 11 , wherein the photo-decomposable base (PDB) layer is patterned.

13. The method of claim 10 , wherein forming a composite layer on a target layer comprises:
forming a photoresist layer using a coating process, the photoresist layer including a photo-decomposable base (PDB) material; and
forming a top coating photo-decomposable base layer during a coating or an exposure process.

14. The method of claim 10 , further comprising forming a top surface water-resistant coating in a separate coating process.

15. The method of claim 10 , wherein a top surface water-resistant coating is self-generated during a photoresist coating process.

Assignees

• Semiconductor Mfg Int Shanghai Corp

Inventors

• Hu Huayong

Classifications

• C07C51/00

  Preparation of carboxylic acids or their salts, halides or anhydrides (of acids by hydrolysis of oils, fats or waxes C11C) · CPC title

• C07C59/21

  containing halogen · CPC title

• C07C229/24

  having more than one carboxyl group bound to the carbon skeleton, e.g. aspartic acid · CPC title

• C07C59/347

  containing keto groups · CPC title

• C07C55/08

  Malonic acid · CPC title