Continuous plasma etch process

Patent metadata

Field	Value
Publication number	US-9530658-B2
Application number	US-201514825115-A
Country	US
Kind code	B2
Filing date	Aug 12, 2015
Priority date	May 1, 2013
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A method for processing a substrate in a process chamber is provided. A plurality of cycles is provided to process the substrate, wherein each cycle comprises the steps of providing a flow of a first process gas into the process chamber, stopping the flow of the first process gas into the process chamber, providing a flow of a first transition gas into the process chamber, wherein the first transition gas neutralizes a component of the first process gas, stopping the flow of the first transition gas into the process chamber, providing a flow of a second process gas into the process chamber, stopping the second process gas into the process chamber, and maintaining a continuous plasma during the cycle.

First claim

What is claimed is:

1. A method for processing a substrate in a process chamber, comprising:
providing a plurality of cycles to process the substrate, wherein each cycle comprises the steps of:
providing a flow of a first process gas into the process chamber;
performing a first process to etch or provide a protective layer on the substrate with the first process gas;
stopping the flow of the first process gas into the process chamber;
providing a flow of a first transition gas into the process chamber;
neutralizing a component of the first process gas with the first transition gas;
stopping the flow of the first transition gas into the process chamber;
providing a flow of a second process gas into the process chamber;
performing a second process to etch or provide a protective layer on the substrate with the second process gas;
stopping the flow of the second process gas into the process chamber; and
maintaining a continuous plasma during the cycle.

2. The method, as recited in claim 1 , wherein the first transition gas is flowed for less than 5 seconds each cycle.

3. The method, as recited in claim 1 , wherein the providing the flow of the first process gas and the providing the flow for the second process gas are each for a period at least 7 times a period for providing the flow of the first transition gas.

4. The method, as recited in claim 1 , wherein the first transition gas is flowed for a period of less than 3 seconds for each cycle.

5. The method, as recited in claim 1 , wherein the first transition gas is inert to a plasma formed from the second process gas.

6. The apparatus, as recited in claim 1 , wherein the providing the flow of the first process gas and the providing the flow for the second process gas are each for a period at least 7 times a period for providing the flow of the first transition gas.

7. The method of claim 1 , wherein the first process is an etching process and the second process provides a protective layer.

8. The method of claim 1 , wherein the first process provides a protective layer and the second process provides an etching process.

9. The method, as recited in claim 1 , wherein each cycle further comprises providing a flow of a second transition gas into the process chamber, wherein the second transition gas neutralizes a component of the second process gas.

10. The method, as recited in claim 9 , wherein each cycle further comprises:
providing a flow of a third process gas into the process chamber; performing a third process to etch or provide a protective layer on the substrate with the third process gas, wherein each step in the cycle is isolated while maintaining the continuous plasma during the cycle.

11. The method, as recited in claim 1 , wherein the first process gas comprises an etch component, and wherein the first transition gas comprises a scavenging component which scavenges the etch component.

12. The method, as recited in claim 11 , wherein the etch component is fluorine and wherein the scavenging component is N 2 .

13. The method, as recited in claim 1 , further comprising providing a pulsed bias voltage, wherein the pulsed bias voltage provides a higher bias voltage when the flow of the first process gas is provided and provides a lower bias voltage when the flow of the first transition gas is provided.

14. The method, as recited in claim 13 , wherein each cycle further comprises providing a flow of a second transition gas into the process chamber, wherein the second transition gas neutralizes a component of the second process gas.

15. The method, as recited in claim 14 , wherein the first process gas comprises an etch component, and wherein the first transition gas comprises a scavenging component which scavenges the etch component.

16. The method, as recited in claim 15 , wherein the etch component is fluorine and wherein the scavenging component is N 2 .

17. An apparatus, comprising:
a plasma processing chamber, comprising:
a chamber wall forming a plasma processing chamber enclosure;
a substrate support for supporting a wafer within the plasma processing chamber enclosure;
a pressure regulator for regulating the pressure in the plasma processing chamber enclosure;
at least one electrode for providing power to the plasma processing chamber enclosure for sustaining a plasma;
a gas inlet for providing gas into the plasma processing chamber enclosure; and
a gas outlet for exhausting gas from the plasma processing chamber enclosure;

at least one RF power source electrically connected to the at least one electrode;
a bias voltage source for providing a bias voltage to the substrate support;

a gas source in fluid connection with the gas inlet; and
a controller controllably connected to the gas source, the bias voltage source, and the at least one RF power source, comprising:
at least one processor; and
computer readable media executable by the at least one processor, comprising:
computer readable code configured to direct the plasma processing chamber to provide a plurality of cycles, wherein each cycle comprises the steps of:
providing a flow of a first process gas into the process chamber;
performing a first process to etch or provide a protective layer on the substrate with the first process gas;
stopping the flow of the first process gas into the process chamber;
providing a flow of a first transition gas into the process chamber;
neutralizing a component of the first process gas with the first transition gas;
stopping the flow of the first transition gas into the process chamber;
providing a flow of a second process gas into the process chamber;
performing a second process to etch or provide a protective layer on the substrate with the second process gas;
stopping the flow of the second process gas into the process chamber; and
maintaining a continuous plasma during the cycle.

18. The apparatus, as recited in claim 17 , wherein the computer readable media further comprises computer readable code for providing a pulsed bias voltage, wherein the pulsed bias voltage provides a higher bias voltage when the flow of the first process gas is provided and provides a lower bias voltage when the flow of the first transition gas is provided.

19. The apparatus, as recited in claim 17 , wherein each cycle further comprises providing a flow of a second transition gas into the process chamber, wherein the second transition gas neutralizes a component of the second process gas.

20. The method, as recited in claim 19 , wherein each cycle further comprises providing a flow of a third process gas into the process chamber; performing a third process to etch or provide a protective layer on the substrate with the third process gas, wherein each step in the cycle is isolated while maintaining the continuous plasma during the cycle.

21. The apparatus, as recited in claim 17 , wherein the first process gas comprises an etch component, and wherein the first transition gas comprises a scavenging component which scavenges the etch component.

22. The apparatus, as recited in claim 21 , wherein the etch component is fluorine and wherein the scavenging component is N 2 .

Assignees

• Lam Res Corp

Inventors

• Lee Wonchul
• Fu Qian

Classifications

• H10P72/0421

  for drying etching · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P50/268

  of silicon-containing layers · CPC title

• H10P50/242 Primary

  of Group IV materials · CPC title

• H01J37/32449

  Gas control, e.g. control of the gas flow · CPC title