Methods for etching materials using synchronized RF pulses

Patent metadata

Field	Value
Publication number	US-9269587-B2
Application number	US-201314020773-A
Country	US
Kind code	B2
Filing date	Sep 6, 2013
Priority date	Sep 6, 2013
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

Embodiments of the present invention provide methods for etching a material layer using synchronized RF pulses. In one embodiment, a method includes providing a gas mixture into a processing chamber, applying a first RF source power at a first time point to the processing chamber to form a plasma in the gas mixture, applying a first RF bias power at a second time point to the processing chamber to perform an etching process on the substrate, turning off the first RF bias power at a third time point while continuously maintaining the first RF source power on from the first time point through the second and the third time points, and turning off the first RF source power at a fourth time point while continuously providing the gas mixture to the processing chamber from the first time point through the second, third and fourth time points.

First claim

The invention claimed is:

1. A method of etching a material layer disposed on a substrate using synchronized RF pulses comprising:
providing a gas mixture into a processing chamber having a substrate disposed therein;
applying a first RF source power at a first time point to the processing chamber to form a plasma in the gas mixture;
applying a first RF bias power at a second time point and a third time point to the processing chamber to perform an etching process on the substrate while continuously applying the first RF source power in the processing chamber from the first time point through the second and the third time points;
applying a second RF bias power at the second time point while continuously applying the first RF bias power and the first RF source power in the processing chamber;
turning off the second RF bias power at the third time point applied to the processing chamber while continuously maintaining the first RF source and the first RF bias power on from the second time point through the third time points; and
turning off the first RF source power and the first RF bias power at a fourth time point applied to the processing chamber while continuously providing the gas mixture to the processing chamber from the first time point through the second, third and fourth time points.

2. The method of claim 1 , further comprising:
applying a preliminary RF source power to the processing chamber prior to applying the first RF source power in the gas mixture.

3. The method of claim 2 , wherein applying the preliminary RF source power further comprises:
applying a preliminary RF bias power to the processing chamber while applying the preliminary RF source power.

4. The method of claim 1 , wherein applying the first RF source power at the first time point further comprises:
applying the first RF source power for a first time period between about 1 microseconds and about 4000 microseconds.

5. The method of claim 1 , wherein applying the first RF source power at the first time point further comprises:
performing a pre-coating process to form a pre-coating layer on the substrate.

6. The method of claim 1 , wherein applying the first RF bias power at the second time point further comprises:
applying the first RF bias power between about 10 microseconds and about 8800 microseconds.

7. The method of claim 1 , wherein turning off the second RF bias power at the third time point further comprises:
continuously applying the first RF source power for between about 1 microseconds and about 4000 microseconds.

8. The method of claim 7 , wherein continuously applying the first RF source power in the processing chamber further comprises:
performing a post-coating process to form a post-coating layer on the substrate.

9. The method of claim 1 , wherein continuously supplying the gas mixture into the processing chamber for at fourth time period comprises supplying the gas mixture for between about 10 microseconds and about 8800 microseconds.

10. The method of claim 9 , further comprising:
performing a pump/purge process in the processing chamber while continuously supplying the gas mixture.

11. The method of claim 9 , wherein the gas mixture continuously supplied to the processing chamber during the fourth time period includes an inert gas or a carrier gas.

12. The method of claim 1 , wherein the gas mixture includes at least a fluorine based gas and a polymer-rich carbon containing gas.

13. The method of claim 1 , wherein the first RF source power has a frequency of about 162 MHz.

14. The method of claim 1 , wherein the first RF bias power has a frequency of about 60 MHz.

15. The method of claim 1 , wherein the step of the applying the first RF source power at the first time point and the step of applying the first RF bias power and the second RF bias power at the second time point are repeatedly performed.

16. A method for etching a material layer disposed on a substrate comprising:
performing a pre-coating process on a substrate by supplying a gas mixture into a processing chamber and forming a plasma from the gas mixture by applying a first RF source power in the gas mixture;
performing an etching process on the substrate by applying a first RF bias power and a second RF bias power into the processing chamber while continuously applying the first RF source power in the processing chamber; and
performing a post-coating process on the substrate by turning off the first RF bias power and a second RF bias power applied into the processing chamber while continuously applying the first RF source power in the processing chamber, wherein the second RF bias power is turned off prior to the first RF bias power.

17. The method of claim 16 , further comprising:
performing a pump/purge process in the processing chamber while turning off the first RF source power but continuously supplying the gas mixture into the processing chamber.

18. The method of claim 16 , wherein the substrate includes a material layer disposed thereon, wherein the material layer is a silicon oxide layer, silicon nitride, alphamos silicon, or a composite layer including silicon oxide and polysilicon or silicon oxide and silicon nitride.

19. The method of claim 16 , wherein the gas mixture includes at least a fluorine based gas and a polymer-rich carbon containing gas.

Assignees

• Applied Materials Inc

Inventors

• Shimizu Daisuke
• Kim Jong Mun
• Kawasaki Katsumasa
• Shoji Sergio Fukuda

Classifications

• H10P50/283 Primary

  by chemical means · CPC title

• H10P50/242 Primary

  of Group IV materials · CPC title

• H01J37/32091

  the radio frequency energy being capacitively coupled to the plasma · CPC title

• H01J2237/334

  Etching · CPC title

• H01L21/31116

  Electricity · mapped topic