Enhanced etch selectivity using halides

Patent metadata

Field	Value
Publication number	US-12315733-B2
Application number	US-202418429554-A
Country	US
Kind code	B2
Filing date	Feb 1, 2024
Priority date	Feb 7, 2023
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A method includes performing a dry etch process to remove a portion of a first layer disposed on a second layer of a stack of alternating layers. The first layer includes a first material and the second layer includes a second material different from the first material, and the dry etch process forms a passivation layer including a byproduct on surfaces of the second material. A amount of first material of the portion of the first layer remains after performing the dry etch process, The method further includes introducing a halide gas to enhance the passivation layer on the surfaces of the second material.

First claim

What is claimed is:

1. A method comprising:
performing a dry etch process to remove a portion of a first layer disposed on a second layer of a stack of alternating layers, wherein the first layer comprises a first material and the second layer comprises a second material different from the first material, wherein the dry etch process forms a passivation layer comprising a byproduct on surfaces of the second material, and wherein an amount of first material of the portion of the first layer remains after performing the dry etch process; and
introducing a halide gas to at least partially repair the passivation layer on the surfaces of the second material.

2. The method of claim 1 , further comprising, after introducing the halide gas, performing a second dry etch process to remove a second portion of the first layer.

3. The method of claim 1 , wherein the second material comprises germanium (Ge).

4. The method of claim 3 , wherein the second material is silicon-germanium (SiGe).

5. The method of claim 1 , wherein the first material is silicon (Si).

6. The method of claim 1 , wherein the halide gas comprises germanium tetrafluoride (GeF 4 ).

7. The method of claim 1 , wherein the passivation layer comprises ammonium hexafluorogermanate (F 6 GeH 8 N 2 ).

8. The method of claim 1 , further comprising performing a first dry etch step to form the portion of the first layer, wherein the dry etch process is performed as part of a second dry etch step after the first dry etch step.

9. The method of claim 8 , further comprising performing a third dry etch step to remove a remaining portion of the second layer.

10. The method of claim 9 , wherein the first dry etch step, the second dry etch step and the third dry etch step are performed to form a staircase structure of an electronic device.

11. The method of claim 10 , wherein the electronic device comprises a three-dimensional dynamic random-access memory (3D DRAM) device.

12. A method comprising:
forming, from a base structure comprising an etch mask disposed on a stack of alternating layers, a staircase structure of an electronic device, wherein the stack of alternating layers comprises a first layer comprising a first material disposed on a second layer comprising a second material different from the first material, and wherein forming the staircase structure comprises:
performing a first dry etch step to remove a portion of the first layer from a region; and
performing a second dry etch step to remove a remaining portion of the first layer from the region, wherein performing the second dry etch step comprises performing a dry etch process to form a passivation layer comprising a byproduct on surfaces of the second material, and introducing a halide gas to enhance at least partially repair the passivation layer on the surfaces of the second material.

13. The method of claim 12 , wherein an amount of the portion of the first layer remains after performing the dry etch process.

14. The method of claim 12 , wherein the second material comprises germanium (Ge).

15. The method of claim 14 , wherein the second material is silicon-germanium (SiGe).

16. The method of claim 12 , wherein the first material is silicon (Si).

17. The method of claim 12 , wherein the halide gas comprises germanium tetrafluoride (GeF 4 ).

18. The method of claim 12 , wherein the passivation layer comprises ammonium hexafluorogermanate (F 6 GeH 8 N 2 ).

19. The method of claim 12 , wherein forming the staircase structure further comprises performing a third dry etch step to remove a remaining portion of the second layer from the region.

20. The method of claim 12 , wherein the electronic device comprises a three-dimensional dynamic random-access memory (3D DRAM) device.

Assignees

• Applied Materials Inc

Inventors

• Knapp David
• Qiao Feng
• Zhou Hailong
• He Junkai
• Fu Qian
• Saly Mark J
• Anthis Jeffrey
• Choi Jayoung

Classifications

• H10P50/242 Primary

  of Group IV materials · CPC title

• H10P50/268

  of silicon-containing layers · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10P50/283

  by chemical means · CPC title

• H10B12/01 Primary

  Manufacture or treatment · CPC title