Removing a residual photo-mask fence in photolithography

• US 10,639,679 B2
• Filed: 04/03/2017
• Issued: 05/05/2020
• Est. Priority Date: 04/03/2017
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Deligianni, Hariklia, Doris, Bruce B., O'Sullivan, Eugene J., Wang, Naigang
• Primary Examiner(s): Ahmed, Shamim
• Application Number:
  US15/477,416
• Publication Number:
  US 20180286666A1
• Time in Patent Office: Days
• Field of Search: None
• CPC Class Codes: B08B 3/08 the liquid having chemical or dissolving effect substances used, see the relevant classes
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture

Abstract

A first material is filled during a semiconductor fabrication process in a space bound on at least one side by a fence formation created as a result of an etching operation. A solvent-removable material is deposited such that the solvent-removable material encapsulates at least that portion of the fence formation which is protruding from the structure such that a height of the fence formation exceeds a height of the structure. The portion of the fence formation which is protruding from the structure and a first portion of the solvent-removable material are removed by planarization. A second portion of the solvent-removable material is removed by dissolving in a solvent, the second portion remaining after removal by the planarization of the first portion of the solvent-removable material.

Claims

1. A method comprising:

filling during a semiconductor fabrication process, in a space bound on at least one side by a fence formation, a first material, wherein the fence formation is created as a result of an etching operation using a photo-mask to form a structure;

depositing a solvent-removable material such that the solvent-removable material encapsulates at least a portion of the fence formation which is protruding from the structure such that a height of the fence formation exceeds a height of the structure;

removing by planarization, the portion of the fence formation which is protruding from the structure, and a first portion of the solvent-removable material; and

removing by dissolving in a solvent, a second portion of the solvent-removable material, the second portion remaining after removal by the planarization of the first portion of the solvent-removable material.

2. The method of claim 1, further comprising:

stopping the planarization at a layer of the structure.

3. The method of claim 2, wherein the layer of the structure is a hard mask layer associated with the structure.

4. The method of claim 1, wherein the planarization comprises a chemical-mechanical planarization (CMP) process.

5. The method of claim 1, further comprising:

performing the etching operation such that some materials removed by the etching operation redeposit on at least one surface of the structure to form the fence formation, and wherein the etching operation creates the space bound on the at least one side by the fence formation.

6. The method of claim 1, wherein the etching operation is an ion-beam etching (IBE) operation, and wherein the some materials of the fence formation are hardened by heat produced in the IBE operation.

7. The method of claim 1, wherein a plurality of fence formations is formed on a plurality of surfaces of the structure.

8. The method of claim 1, wherein the filling the space with the first material causes the first material to be filled at least up to the height of the fence formation.

9. The method of claim 1, wherein the first material and the second material are interchangeable due to a property that is shared by the first material and the solvent-removable material.

10. The method of claim 1, wherein the first material is interchangeable with a material used in the photo-mask due to a property that is shared by the first material and the material used in the photo-mask.