Bottom up molybdenum gapfill

Patent metadata

Field	Value
Publication number	US-12559836-B2
Application number	US-202217877310-A
Country	US
Kind code	B2
Filing date	Jul 29, 2022
Priority date	Jul 29, 2022
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

Embodiments of the disclosure relate to methods for molybdenum gapfill. Additional embodiments provide a method of forming a molybdenum gapfill without substantial voids. Some embodiments of the disclosure are relevant for higher aspect ratio features including DRAM memory cells.

First claim

What is claimed is:

1 . A method of depositing molybdenum gapfill, the method comprising:
exposing a substrate surface with at least one feature formed therein to a first molybdenum precursor and a reductant to form a first gapfill within the at least one feature, the at least one feature having an opening, two sidewalls and extending a depth from a top surface to a bottom surface, the first gapfill having a top thickness on the top surface of at least 20 Ångstroms and a bottom thickness on the bottom surface of at least 10 Ångstroms and the top thickness is greater than the bottom thickness; exposing the substrate surface to a second molybdenum halide precursor to remove a portion of the first gapfill to reduce the top thickness and the bottom thickness, and the top thickness is reduced by a greater amount than the bottom thickness; and repeating formation of the first gapfill.

2 . The method of claim 1 , wherein the opening has a width in a range of 5 nm to 35 nm and an aspect ratio of the at least one feature is greater than or equal to about 20:1.

3 . The method of claim 2 , wherein the opening has a width in a range of 5 nm to 15 nm and the aspect ratio of the at least one feature is greater than or equal to about 50:1.

4 . The method of claim 2 , wherein the first gapfill is entirely removed from the top surface.

5 . The method of claim 1 , wherein the at least one feature forms a memory cell of DRAM.

6 . The method of claim 1 , wherein the first gapfill is formed by a CVD process.

7 . The method of claim 6 , wherein the CVD process is performed without plasma.

8 . The method of claim 1 , wherein the first molybdenum precursor comprises an oxyhalide.

9 . The method of claim 8 , wherein the first molybdenum precursor consists essentially of MoO 2 Cl 2 .

10 . The method of claim 9 , wherein the second molybdenum halide precursor consists essentially of MoCl 5 .

11 . The method of claim 1 , wherein the substrate is maintained at a temperature in a range of about 500° C. to about 600° C. during formation of the first gapfill.

12 . The method of claim 1 , wherein the substrate surface is purged after formation of the first gapfill and before exposure to the second molybdenum halide precursor.

13 . The method of claim 1 , wherein removing the portion of the first gapfill removes a thickness in a range of about 10 Å to about 50 Å.

14 . The method of claim 1 , wherein the portion of the first gapfill is removed from near the top of the at least one feature and the method forms the first gapfill in a bottom-up fashion.

15 . The method claim 1 , wherein the first gapfill contains voids and removing a portion of the first gapfill removes the voids.

16 . The method of claim 15 , wherein the method forms a molybdenum gapfill without substantial voids.

17 . The method of claim 1 , wherein the substrate surface is purged after exposure to the second molybdenum halide precursor and before repeating formation of the first gapfill.

18 . The method of claim 1 , further comprising repeating formation and removal of the first gapfill to fill the at least one feature.

19 . The method of claim 18 , wherein formation and removal form a dep-etch cycle and a number of cycles in a range of about 200 to about 400 are performed.

20 . A method of depositing molybdenum gapfill, the method comprising:
exposing a substrate surface with at least one feature formed therein to MoO 2 Cl 2 and H 2 to form a first gapfill within the at least one feature, the at least one feature having an opening, two sidewalls and extending a depth from a top surface to a bottom surface, the first gapfill having a top thickness on the top surface of at least 20 Ångstroms and a bottom thickness on the bottom surface of at least 10 Ångstroms and the top thickness is greater than the bottom thickness; exposing the substrate surface to MoCl 5 to remove a portion of the first gapfill to reduce the top thickness and the bottom thickness, and the top thickness is reduced by a greater amount than the bottom thickness; and repeating formation and removal of the first gapfill to entirely fill the at least one feature in a bottom-up fashion.

Assignees

• Applied Materials Inc

Inventors

• Haddadin Rand
• Bhatnagar Kunal

Classifications

• H10W20/098

  by filling between adjacent conductive parts · CPC title

• H10B12/02

  for one transistor one-capacitor [1T-1C] memory cells · CPC title

• C23C16/08

  from metal halides · CPC title

• C23C16/56

  After-treatment · CPC title

• C23C16/4408

  by purging residual gases from the reaction chamber or gas lines · CPC title