Method of improving deposition induced CD imbalance using spatially selective ashing of carbon based film

Patent metadata

Field	Value
Publication number	US-10978302-B2
Application number	US-201815974172-A
Country	US
Kind code	B2
Filing date	May 8, 2018
Priority date	Nov 29, 2017
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A method for forming features over a wafer with a carbon based deposition is provided. The carbon based deposition is pretuned, wherein the pretuning causes a non-uniform removal of some of the carbon based deposition. An oxide deposition of a silicon oxide based material is deposited through an atomic layer deposition process, wherein the depositing the oxide deposition causes a non-uniform removal of some of the carbon based deposition, which is complementary to the non-uniform removal of some of the carbon based deposition by the pretuning.

First claim

What is claimed is:

1. A method for forming features over a wafer with a carbon based deposition, comprising:
pretuning the carbon based deposition, wherein the pretuning causes a first non-uniform removal of some of the carbon based deposition; and
depositing an oxide deposition of a silicon oxide based material through an atomic layer deposition process, wherein the depositing the oxide deposition causes a second non-uniform removal of some of the carbon based deposition, which is complementary to the first non-uniform removal of some of the carbon based deposition by the pretuning.

2. The method, as recited in claim 1 , wherein the second non-uniform removal of some of the carbon based deposition by the oxide deposition is complementary to the first non-uniform removal of some of the carbon based deposition by the pretuning in that the combination of the second non-uniform removal of some of the carbon based deposition by the depositing the oxide deposition and the first non-uniform removal of some of the carbon based deposition by the pretuning results in a more uniform removal of the carbon based deposition than the second non-uniform removal of some of the carbon based deposition by the depositing the oxide deposition.

3. The method, as recited in claim 2 , wherein the more uniform removal is a more uniform removal across the wafer.

4. The method, as recited in claim 1 , further comprising:
removing the carbon based deposition; and
etching an etch layer below the oxide deposition, using the oxide deposition as a mask.

5. The method, as recited in claim 1 , wherein the pretuning the carbon based deposition, comprises:
providing a pretuning gas comprising oxygen and at least one of Ar or nitrogen,
transforming the pretuning gas into a plasma, which causes a non-uniform removal of some of the carbon based deposition; and
stopping the pretuning gas.

6. The method, as recited in claim 5 , wherein the pretuning gas comprises oxygen and argon, wherein a ratio of the oxygen to argon is between 2:1 to 1:2.

7. The method, as recited in claim 1 , wherein the pretuning removes less than 20 {acute over (Å)} thickness of the carbon based deposition.

8. The method, as recited in claim 7 , wherein the depositing the oxide deposition and the pretuning provide a removal range across the wafer of the carbon based deposition of less than 10 {acute over (Å)}.

9. The method, as recited in claim 1 , wherein the pretuning removes the carbon based deposition in a dome shaped profile and wherein the depositing the oxide deposition removes the carbon based deposition in a bowl shaped profile.

10. The method, as recited in claim 1 , wherein the depositing the oxide deposition comprises:
providing a lower energy oxide deposition of a plurality of cycles, wherein each cycle comprises:
flowing a precursor gas;
flowing an oxidation gas;
providing a first RF power to transform the oxidation gas into a plasma; and

providing a higher energy oxide deposition of a plurality of cycles, wherein each cycle comprises:
flowing a precursor gas;
flowing an oxidation gas; and
providing a second RF power to transform the oxidation gas into a plasma, wherein the second RF power is higher than the first RF power.

11. The method, as recited in claim 1 , further comprising providing at least one of a feedback or feedforward input to optimize the pretuning.

12. The method, as recited in claim 1 , further comprising forming a carbon based deposition over the wafer.

Assignees

• Lam Res Corp

Inventors

• Karim Ishtak
• Agarwal Pulkit
• Abel Joseph
• Kumar Purushottam
• Lavoie Adrien

Classifications

• H10P50/287

  by chemical means · CPC title

• H10P76/204

  of organic photoresist masks · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P14/6687

  the compound comprising silicon and nitrogen · CPC title