Method for graded anti-reflective coatings by physical vapor deposition

Patent metadata

Field	Value
Publication number	US-10096725-B2
Application number	US-201414531549-A
Country	US
Kind code	B2
Filing date	Nov 3, 2014
Priority date	Nov 13, 2013
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A method for forming an anti-reflective coating (ARC) includes positioning a substrate below a target and flowing a first gas to deposit a first portion of the graded ARC onto the substrate. The method includes gradually flowing a second gas to deposit a second portion of the graded ARC, and gradually flowing a third gas while simultaneously gradually decreasing the flow of the second gas to deposit a third portion of the graded ARC. The method also includes flowing the third gas after stopping the flow of the second gas to form a fourth portion of the graded ARC. In another embodiment a film stack having a substrate having a graded ARC disposed thereon is provided. The graded ARC includes a first portion, a second portion disposed on the first portion, a third portion disposed on the second portion, and a fourth portion disposed on the third portion.

First claim

What is claimed is:

1. A method for forming a graded anti-reflective coating in a physical vapor deposition processing chamber comprising:
positioning a substrate on a substrate support in the processing chamber below a target;
flowing a first inert gas into the processing chamber to sputter the target to deposit a first portion of the graded anti-reflective coating onto the substrate, the first portion having a first refractive index;
gradually flowing a second gas into the processing chamber to deposit a second portion of the graded anti-reflective coating onto the substrate, the second portion having a second refractive index that is less than the first refractive index;
gradually flowing a third gas into the processing chamber while simultaneously gradually decreasing the flow of the second gas into the processing chamber to deposit a third portion of the graded anti-reflective coating onto the substrate, the third portion having a third refractive index that is less than the second refractive index;
arriving at a final value of a flow rate of the third gas to tune a stress level of the graded anti-reflective coating; and
flowing the third gas into the processing chamber after stopping the flow of the second gas to form a fourth portion of the graded anti-reflective coating, the fourth portion having a fourth refractive index that is less than the third refractive index.

2. The method of claim 1 , wherein the first gas is argon gas flowed at about 30 sccm.

3. The method of claim 1 , wherein the second gas and third gas are selected from a group comprising nitrogen gas (N 2 ), nitrogen dioxide (NO 2 ), fluorine gas (F 2 ), oxygen gas (O 2 ), hydrogen gas (H2), H 2 O in vapor form, methane (CH4), carbon monoxide (CO), methane (CH 4 ), and carbon dioxide (CO 2 ).

4. The method of claim 3 , wherein the second gas is nitrogen gas, the third gas is oxygen gas and that target comprises silicon.

5. The method of claim 4 , wherein the first portion comprises silicon.

6. The method of claim 5 , wherein the nitrogen gas is gradually flowed at about 100 sccm and the second portion comprises silicon and nitrogen.

7. The method of claim 6 , wherein the oxygen gas is gradually flowed at between about 0 sccm to about 100 sccm, and the third portion comprises silicon, nitrogen and oxygen.

8. The method of claim 7 , wherein the nitrogen gas is gradually flowed while the oxygen gas is gradually flowed.

9. The method of claim 7 , wherein the nitrogen gas is gradually extinguished while the oxygen gas is gradually flowed.

10. The method of claim 9 , wherein the fourth portion comprises silicon and oxygen.

11. A method for forming a graded anti-reflective coating comprising:
positioning a substrate on a substrate support in a physical vapor deposition chamber below a silicon target;
sputtering the silicon target with argon gas to deposit a first portion of the graded anti-reflective coating onto the substrate, the first portion having a first refractive index;
gradually flowing nitrogen gas into the processing chamber to deposit a second portion of the graded anti-reflective coating onto the substrate, the second portion having a second refractive index that is less than the first refractive index;
gradually flowing oxygen gas into the processing chamber while simultaneously gradually decreasing the flow of the nitrogen gas into the processing chamber to deposit a third portion of the graded anti-reflective coating onto the substrate, the third portion having a third refractive index that is less than the second refractive index;
arriving at a final value of a flow rate of the oxygen gas to tune a stress level of the graded anti-reflective coating; and
flowing the oxygen gas into the processing chamber after stopping the flow of the nitrogen gas to form a fourth portion of the graded anti-reflective coating onto the substrate, the fourth portion having a fourth refractive index that is less than the third refractive index.

12. The method of claim 11 , wherein the physical vapor deposition chamber pressure is less than about 100 mTorr and at room temperature.

13. The method of claim 12 , wherein DC power in the physical vapor deposition chamber is less than about 20 kW and pulsed at a frequency of about 100 kHz and a duty cycle of about 97%.

14. The method of claim 13 , wherein the physical vapor deposition chamber pressure is about 10 mTorr and the DC power is about 6 kW.

Assignees

• Applied Materials Inc

Inventors

• Cao Yong
• Diehl Daniel Lee
• Wang Rongjun
• Tang Xianmin
• Chen Tai-Chou Papo
• Xu Tingjun

Classifications

• C23C14/35

  by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} · CPC title

• C23C14/0676

  Oxynitrides · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• H01L31/02161 Primary

  Electricity · mapped topic

• C23C14/0042

  Controlling partial pressure or flow rate of reactive or inert gases with feedback of measurements · CPC title