Granted Patent B2

US 12,315,732 · App. 17/837,958 · Granted May 27, 2025

Inventors: Daisuke Shimizu (Milpitas, CA); Li Ling (Santa Clara, CA); Hikaru Watanabe (Santa Clara, CA); Kenji Takeshita (Santa Clara, CA)

H01L21/3065H01J37/32128H01J37/32146H01J37/32449H01J2237/334

Abstract

Claims (34)

1. A method for etching a substrate in a plasma etch chamber, the method comprising:

exposing the substrate disposed on a substrate supporting surface of a substrate support to a plasma within the processing chamber; and

applying a voltage waveform to an electrode disposed in the substrate support while the substrate is exposed to the plasma during a plurality of macro etch cycles, each macro etch cycle including a first macro etch period and a second macro etch period, the macro etch period comprises a plurality of micro etch cycles, each micro etch cycle having a bias power on (BPON) period and a bias power off (BPOFF) period, a duration of the BPON period being less than a duration of the BPOFF period, and bias power predominantly not applied to the electrode during the second macro etch period.

2. The method of claim 1 , wherein the BPON period of one of the micro etch cycles is less than 45% of the BPOFF period.

3. The method of claim 1 , wherein the BPON period of one of the micro etch cycles is between about 10% and about 45% of the BPOFF period.

4. The method of claim 1 , wherein the plurality of macro etch cycles includes a first macro etch cycle occurring prior to a second macro etch cycle, and wherein a BPON period of one of the micro etch cycles of the first macro etch cycle is greater than a BPON period of one of the micro etch cycles of the second macro etch cycle.

5. The method of claim 1 , wherein a frequency of the macro etch cycles of the plurality of macro etch cycles decreases as the substrate is etched.

6. The method of claim 1 , wherein the frequency of the macro etch cycles is between about 2 to about 100 Hz.

7. The method of claim 1 , wherein a frequency of the micro etch cycles is between about 25 to about 500 KHz.

8. The method of claim 7 , wherein the frequency of the macro etch cycles is between about 2 to about 100 Hz.

9. The method of claim 1 , wherein each micro etch cycle is at least an order of magnitude less than the macro etch cycle.

10. The method of claim 1 further comprising:

forming the plasma from a processing gas comprising carbon and at least one halogen.

11. The method of claim 10 , wherein a dielectric material is removed from the substrate during the BPON period.

12. The method of claim 11 , wherein the dielectric material is an oxide material, nitride material, or a stack of oxide and nitride layer pairs.

13. The method of claim 11 , wherein the dielectric material includes at least one oxide layer and at least one nitride layer.

14. The method of claim 11 , wherein the processing gas one or both of C x F z and C x H y F z , wherein x, y and z are integers.

15. A method for etching a substrate in a plasma etch chamber, the method comprising:

forming a plasma from a processing gas containing carbon and at least one halogen;

exposing a dielectric layer disposed on the substrate to the plasma within the plasma etch chamber; and

applying bias power to an electrode disposed in a substrate support supporting the substrate within the plasma etch chamber while exposed to the plasma during a plurality of macro etch cycles until an end point is reached, each macro etch cycle including a first macro etch period and a second macro etch period, the macro etch period comprises a plurality of micro etch cycles, each micro etch cycle having a bias power on (BPON) period and a bias power off (BPOFF) period, a duration of the BPON period being less than a duration of the BPOFF period, bias power predominantly not applied to the electrode during the second macro etch period, wherein in at least macro etch cycle:

the BPON period is at least two orders of magnitude shorter in duration than the first macro etch period; and

the BPOFF period is at least two orders of magnitude shorter in duration than the second macro etch period.

16. The method of claim 15 , wherein the BPON period of one of the micro etch cycles is less than 45% of the BPOFF period.

17. The method of claim 15 , wherein the BPON period of one of the micro etch cycles is between about 10% and about 45% of the BPOFF period.

18. The method of claim 15 , wherein the plurality of macro etch cycles includes a first macro etch cycle occurring prior to a second macro etch cycle, and wherein a BPON period of one of the micro etch cycles of the first macro etch cycle is greater than a BPON period of one of the micro etch cycles of the second macro etch cycle.

19. The method of claim 15 , wherein a frequency of the macro etch cycles of the plurality of macro etch cycles decreases as the substrate is etched.

20. A plasma etch chamber comprising a chamber body having an interior volume;

a substrate support disposed in the interior volume of the chamber body, the substrate support configured to retain a substrate thereon during processing, the substrate support having an electrode;

a bias power control system coupled to the electrode;

a gas panel configured to provide a processing gas to the interior volume; and

a controller configured to:

maintain a plasma within the processing chamber formed from the processing gas; and

apply a voltage waveform to the electrode while the substrate disposed on the substrate support is exposed to the plasma during a plurality of macro etch cycles, each macro etch cycle including a first macro etch period and a second macro etch period, the macro etch period comprises a plurality of micro etch cycles, each micro etch cycle having a bias power on (BPON) period and a bias power off (BPOFF) period, a duration of the BPON period being less than a duration of the BPOFF period, and bias power is predominantly not applied to the electrode during the second macro etch period.

Assignments (1)

Continuity (1)

References Cited (400)