Method for improving deposition process

Patent metadata

Field	Value
Publication number	US-12112930-B2
Application number	US-201916528781-A
Country	US
Kind code	B2
Filing date	Aug 1, 2019
Priority date	Aug 31, 2018
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

A method includes placing a wafer on a wafer holder, depositing a film on a front surface of the wafer, and blowing a gas through ports in a redistributor onto a back surface of the wafer at a same time the deposition is performed. The gas is selected from a group consisting of nitrogen (N 2 ), He, Ne, and combinations thereof.

First claim

What is claimed is:

1. A method comprising:
placing a wafer on a wafer holder;
depositing a film on a front surface of the wafer; and
blowing a backside gas through ports in a redistributor onto a back surface of the wafer at a same time the deposition is performed, wherein the backside gas is selected from a group consisting of nitrogen (N 2 ), He, Ne, and combinations thereof, wherein the redistributor separates a space on a backside of the wafer into a first portion and a second portion, wherein the backside gas is blown into the first portion, wherein the backside gas is redistributed from the first portion into the second portion through the ports, with the back surface of the wafer exposed to the second portion, wherein a width of the wafer is smaller than a width of the second portion, wherein the backside gas is the only gas in the first portion and the second portion while blowing the backside gas through the ports.

2. The method of claim 1 , wherein the ports are arranged in a grid pattern.

3. The method of claim 1 , wherein the ports are arranged in a cross pattern.

4. The method of claim 1 , wherein the ports comprise a circular shape.

5. The method of claim 1 , wherein the ports comprise a rectangular shape.

6. The method of claim 1 , wherein the ports are distributed so that a first total number of ports along an x-axis is between 1 and 1000, and a second total number of ports along a y-axis is between 1 and 1000.

7. The method of claim 1 , wherein a distance between nearest adjacent ports is between about 1 mm and about 100 mm.

8. A method comprising:
depositing a first metal-containing layer on a wafer by a first physical vapor deposition with a first plasma, wherein a first backside gas is blown to a backside of the wafer when the first metal-containing layer is deposited, wherein the first metal-containing layer comprises TaN, wherein the first backside gas comprises argon or H 2 ; and
depositing a second metal-containing layer over the first metal-containing layer by a second physical vapor deposition with a second plasma, wherein the second metal-containing layer comprises TiN, wherein a second backside gas is blown to the backside of the wafer when the second metal-containing layer is deposited, and wherein the first backside gas is different from the second backside gas, wherein the backside of the wafer is free from exposure to argon and H 2 while the second backside gas is blown.

9. The method of claim 8 , wherein the first backside gas comprises argon.

10. The method of claim 8 , wherein the second backside gas comprises nitrogen.

11. The method of claim 10 , wherein the first backside gas is free from nitrogen.

12. A method comprising:
forming a bottom electrode layer on a substrate, wherein the bottom electrode layer comprises a first sublayer and a second sublayer, wherein forming the second sublayer of the bottom electrode layer comprises a first physical vapor deposition comprising:
sputtering a Ti metal from a first target, wherein in the sputtering, plasma is generated from a first gas, wherein the first gas comprises N 2 ; and
conducting a second gas onto a back surface of the substrate, wherein the second gas is selected from a group consisting of nitrogen (N 2 ), He, Ne, and combinations thereof;

forming a magnetic tunnel junction (MTJ) layer over the bottom electrode layer;
forming a top electrode layer over the MTJ layer; and
patterning the top electrode layer, the MTJ layer, and the bottom electrode layer to form a magnetic random access memory (MRAM) cell, wherein the top electrode layer comprises a first conductive layer comprising TiN, a second conductive layer comprising Ta, and a third conductive layer comprising TaN.

13. The method of claim 12 , wherein the first gas is free from argon.

14. The method of claim 12 , wherein a DC power used to generate the plasma from the first gas is in a range from about 1 KW to about 30 KW.

15. The method of claim 12 , wherein an arcing rate of the sputtering with conducting the second gas onto the back surface of the substrate is 0.067 times an arcing rate of the sputtering with conducting argon to the back surface of the substrate.

16. The method of claim 12 , wherein the second sublayer is formed over the first sublayer, wherein the first sublayer comprises TaN, wherein the second sublayer comprises TiN.

17. The method of claim 1 , wherein the backside gas is blown into the first portion from a gas inlet, and the gas inlet is completely offset from all of the ports in the redistributor in a plan view.

18. The method of claim 8 , further comprising heating the wafer and the second backside gas to a range between 200° C. and about 450° C. when depositing the second metal-containing layer.

19. The method of claim 16 , wherein the first sublayer of the bottom electrode layer is formed by a second physical vapor deposition comprising:
sputtering a Ta metal from a second target; and
conducting a third gas onto the back surface of the substrate, wherein the third gas comprises argon or H 2 .

20. The method of claim 12 , wherein the first conductive layer of the top electrode layer is formed by a deposition using a plasma, wherein the deposition comprises conducting a fourth gas onto the back surface of the substrate, wherein the fourth gas comprises argon or H 2 .

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Wu Jung-Tang
• Wu Szu-Hua
• Lee Chin-Szu
• Wang Yi-Lin

Classifications

• H10P14/44

  Physical vapour deposition [PVD] · CPC title

• H10P14/412

  Deposition of metallic or metal-silicide materials · CPC title

• H10W20/056

  by filling conductive material into holes, grooves or trenches · CPC title

• H10W20/031 Primary

  of conductive parts of the interconnections · CPC title

• H01J37/3244

  Gas supply means · CPC title