Grain structure engineering for metal gapfill materials

Patent metadata

Field	Value
Publication number	US-12588533-B2
Application number	US-202318225286-A
Country	US
Kind code	B2
Filing date	Jul 24, 2023
Priority date	Jul 24, 2023
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

A method for depositing copper onto a substrate includes grain engineering to control the internal structure of the copper. In some embodiments, the method comprises depositing a grain control layer conformally onto a copper seed layer in a structure on the substrate where the grain control layer is a non-conducting material, etching the grain control layer using a direct deep reactive ion etch (DRIE) process to remove portions of the grain control layer on horizontal surfaces within the structure, and depositing a copper material onto the structure such that at least one grain parameter of the copper material is controlled, at least in part, by a remaining portion of the grain control layer on vertical surfaces of the structure. In some embodiments, the deposited copper material in the structure has a < 111> grain orientation normal to a horizontal surface of the structure.

First claim

The invention claimed is:

1 . A method for controlling gapfill material deposition processes, comprising:
depositing a metal seed layer conformally onto a substrate with at least one structure formed into the substrate; depositing a grain control layer conformally onto the substrate and into the at least one structure, wherein the grain control layer is a non-conducting material; depositing a polymer layer on the substrate in an etch chamber such that at least one exposed corner of the at least one structure is covered during a subsequent etching process; etching the grain control layer using an etch process to remove portions of the grain control layer on horizontal surfaces within the at least one structure; and depositing a metal gapfill material onto the at least one structure such that at least one grain parameter of the metal gapfill material is controlled, at least in part, by a remaining portion of the grain control layer on vertical surfaces of the at least one structure.

2 . The method of claim 1 , wherein the at least one structure includes a trench, a via, or a damascene structure.

3 . The method of claim 1 , wherein the grain control layer is an inorganic dielectric material.

4 . The method of claim 3 , wherein the inorganic dielectric material is SiN, SiO 2 , or SiCN.

5 . The method of claim 1 , wherein the grain control layer is an organic dielectric material.

6 . The method of claim 5 , wherein the organic dielectric material is a fluoropolymer material, a polyimide material, a polybenzoxazole material, or a self-assembled monolayer.

7 . The method of claim 1 , wherein depositing the metal gapfill material onto the at least one structure forms a copper gapfill material in the at least one structure with a < 111 > grain orientation normal to a horizontal surface of the at least one structure.

8 . The method of claim 1 , wherein depositing the metal gapfill material onto the at least one structure forms a copper gapfill material in the at least one structure with a copper grain orientated lengthwise along a length of the at least one structure and wherein the copper grain fills a width of the at least one structure.

9 . The method of claim 1 , wherein the at least one structure on the substrate has sidewalls of 90 degrees or less relative to horizontal surfaces within the at least one structure.

10 . The method of claim 1 , wherein the grain control layer is selected based on adhesion characteristics to the metal seed layer.

11 . The method of claim 1 , wherein the grain control layer has a thickness of approximately 1 nanometer or less.

12 . The method of claim 1 , wherein the at least one structure is a trench or via formed by a lithography process in a photo-imageable organic dielectric material of the substrate.

13 . The method of claim 1 , wherein the method is used in a copper-to-copper hybrid bonding process with a bonding temperature of 250 degrees or less.

14 . The method of claim 1 , wherein the grain control layer remains as part of the at least one structure during subsequent processing of the at least one structure.

15 . The method of claim 1 , wherein the metal gapfill material is deposited using electrochemical plating.

16 . The method of claim 1 , wherein the etch process is a direct deep reactive ion etch (DRIE) process.

17 . A method for depositing copper, comprising:
depositing a grain control layer conformally onto a copper seed layer in at least one structure on a substrate, wherein the grain control layer is a non-conducting material; depositing a polymer layer on the substrate in an etch chamber such that at least one exposed corner of the at least one structure is covered during a subsequent etching process; etching the grain control layer using a direct deep reactive ion etch (DRIE) process to remove portions of the grain control layer on horizontal surfaces within the at least one structure; and depositing a copper gapfill material onto the at least one structure such that at least one grain parameter of the copper gapfill material is controlled, at least in part, by a remaining portion of the grain control layer on vertical surfaces of the at least one structure, wherein deposited copper gapfill material in the at least one structure has a < 111 > grain orientation normal to a horizontal surface of the at least one structure.

18 . The method of claim 17 , wherein the grain control layer is an organic dielectric material.

19 . The method of claim 17 , wherein the grain control layer has a thickness of approximately 1 nanometer or less.

20 . A non-transitory, computer readable medium having instructions stored thereon that, when executed, cause a method for depositing copper to be performed, the method comprising:
depositing a grain control layer conformally onto a copper seed layer in at least one structure on a substrate, wherein the grain control layer is a non-conducting material; depositing a polymer layer on the substrate in an etch chamber such that at least one exposed corner of the at least one structure is covered during a subsequent etching process; etching the grain control layer using a direct deep reactive ion etch (DRIE) process to remove portions of the grain control layer on horizontal surfaces within the at least one structure; and depositing a copper material onto the at least one structure such that at least one grain parameter of the copper material is controlled, at least in part, by a remaining portion of the grain control layer on vertical surfaces of the at least one structure, wherein deposited copper material in the at least one structure has a < 111 > grain orientation normal to a horizontal surface of the at least one structure.

Assignees

• Applied Materials Inc

Inventors

• Lianto Prayudi
• Bernt Marvin Louis
• Chakraborty Tapash
• Lim Yin Wei
• Xu Jing

Classifications

• H10W80/701

  characterised by the pads after the direct bonding · CPC title

• H10W80/327

  characterised by the direct bonding of insulating parts, e.g. of silicon oxide layers · CPC title

• H10W72/9415

  relative to the surface, e.g. recessed, protruding · CPC title

• H10W72/01953

  by etching · CPC title

• H10W72/01951

  Changing the shapes of bond pads · CPC title