Wet etchants including at least one fluorosurfactant etch blocker

• US 9,175,217 B2
• Filed: 04/15/2014
• Issued: 11/03/2015
• Est. Priority Date: 08/06/2007
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Sinha, Nishant, Greeley, J. Neil
• Primary Examiner(s): BOYER, CHARLES I
• Application Number:
  US14/253,005
• Publication Number:
  US 20140225028A1
• Time in Patent Office: 567 Days
• US Class Current: 1/1
• CPC Class Codes: C09K 13/06 with organic material
• CPC Class Codes: C09K 13/08 containing a fluorine compound
• CPC Class Codes: H01L 21/31055 the removal being a chemical etching step, e.g. dry etching etching per se H01L21/311
• CPC Class Codes: H01L 21/31111 by chemical means

Abstract

Methods for preventing isotropic removal of materials at corners faulted by seams, keyholes, and other anomalies in films or other structures include use of etch blockers to cover or coat such corners. This covering or coating prevents exposure of the corners to isotropic etch solutions and cleaning solutions and, thus, prevents higher material removal rates at the corners than at smoother areas of the structure or film. Solutions, including wet etchants and cleaning solutions, that include at least one type of etch blocker are also disclosed, as are systems for preventing higher rates of material removal at corners formed by seams, crevices, or recesses in a film or other structure. Semiconductor device structures in which etch blockers are located so as to prevent isotropic etchants from removing material from corners of seams, crevices, or recesses of a film or other structure at undesirably high rates are also disclosed.

Claims

1. A wet etchant consisting of:

an etch solution consisting of water and buffered oxide etchant; and

at least one etch blocker selected from the group consisting of ZONYL®

FS-62, and NOVEC®

4300.

8. The wet etchant of claim 1, wherein the at least one etch blocker consists of NOVEC®

4300.

9. The wet etchant of claim 1, wherein the at least one etch blacker consists of ZONYL®

FS-62.

2. A wet etchant mixture consisting of:

an etch solution consisting of water and at least one wet etchant; and

a plurality of etch blockers consisting of;

at least one fluorosurfactant; and

at least one surfactant other than the at least one fluorosurfactant, the least one surfactant comprising at least one anionic surfactant.

4. The wet etchant mixture of claim 2, wherein the at least one wet etchant is selected from the group consisting of hydrofluoric acid and buffered oxide etchant.

5. The wet etchant mixture of claim 4, wherein the at least one fluorosurfactant comprises at least one anionic fluorosurfactant.

6. The wet etchant mixture of claim 2, wherein the at least one wet etchant consists of hydrofluoric acid.

7. The wet etchant mixture of claim 2, wherein the at least one wet etchant consists of buffered oxide etchant.

3. A wet etchant mixture consisting of:

an etch solution consisting of water and at least one wet etchant; and

a plurality of etch blockers consisting of;

at least one fluorosurfactant; and

at least one surfactant other than the at least one fluorosurfactant, the least one surfactant comprising at least one nonionic surfactant.