Methods for etching structures with oxygen pulsing

Patent metadata

Field	Value
Publication number	US-11527414-B2
Application number	US-202117369781-A
Country	US
Kind code	B2
Filing date	Jul 7, 2021
Priority date	Aug 18, 2020
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A method for patterning a material layer on a substrate includes forming a hard mask layer on a material layer disposed on a substrate, and etching the material layer through the hard mask layer by simultaneously supplying an etching gas mixture and an oxygen containing gas. The etching gas mixture is supplied continuously and the oxygen containing gas is pulsed.

First claim

We claim:

1. A method for patterning a material layer on a substrate, comprising:
forming a hard mask layer on a material layer disposed on a substrate; and
etching the material layer through an opening of the hard mask layer by an etching gas mixture, and simultaneously forming oxide top portions within the opening of the hard mask layer by supplying an oxygen containing gas,
wherein the etching gas mixture is supplied continuously and the oxygen containing gas is pulsed and does not reach an exposed surface of the material layer.

2. The method of claim 1 , wherein the oxygen containing gas is pulsed at a pulse duration of between 1 seconds and 10 seconds and a duty cycle of between 1:3 and 3:1.

3. The method of claim 1 , wherein the material layer comprises first layers and second layers alternately formed on the substrate.

4. The method of claim 3 , wherein the first layers comprises molybdenum (Mo) and the second layers comprise tungsten (W).

5. The method of claim 3 , wherein
the material layer has a thickness of between 200 nm and 4500 nm, and
the first and second layers each have a thickness of between 10 nm and 30 nm.

6. The method of claim 1 , wherein the hard mask layer comprises tetra-ethyl-orthosilicate (TEOS).

7. The method of claim 1 , wherein the hard mask layer has a thickness of between 500 nm and 2 μm and has openings having a dimension of between 1000 nm and 1300 nm and a pitch between adjacent openings of between 50 nm and 180 nm.

8. The method of claim 1 , further comprising forming an adhesion layer comprising silicon nitride (Si 3 N 4 ) between the material layer and the hard mask layer.

9. The method of claim 1 , wherein
the etching gas mixture comprises SiCl 4 , and
the oxygen containing gas mixture comprises O 2 .

10. The method of claim 9 , wherein a ratio of a flow rate of the oxygen containing gas to a flow rate of the etching gas mixture is between 1:20 and 1:6.

11. A method for etching a material layer on a substrate through a hard mask in a processing chamber, comprising:
supplying an etching gas mixture to a material layer having a hard mask layer formed thereon in a processing chamber; and
simultaneously supplying an oxygen containing gas to top portions of an opening of the hard mask layer in the processing chamber, wherein
the etching gas mixture is supplied continuously and the oxygen containing gas is pulsed and does not reach an exposed surface of the material layer.

12. The method of claim 11 , wherein the oxygen containing gas is pulsed at a pulse duration of between 1 seconds and 10 seconds and a duty cycle of between 1:3 and 3:1.

13. The method of claim 11 , wherein
the material layer comprises first layers comprising molybdenum (Mo) and second layers tungsten (W) alternately formed on the substrate.

14. The method of claim 11 , wherein
the hard mask layer comprises tetra-ethyl-orthosilicate (TEOS).

15. The method of claim 11 , wherein
the etching gas mixture comprises SiCl 4 , and
the oxygen containing gas mixture comprises O 2 .

16. The method of claim 15 , wherein a ratio of a flow rate of the oxygen containing gas to a flow rate of the etching gas mixture is between 1:20 and 1:6.

Assignees

• Applied Materials Inc

Inventors

• Fung Nancy
• Alva Gabriela

Classifications

• H10P50/267 Primary

  using plasmas · CPC title

• H10P50/71 Primary

  using masks for conductive or resistive materials · CPC title

• H01J37/32449 Primary

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

• H01J2237/3341

  Reactive etching · CPC title

• H01L21/32139 Primary

  Electricity · mapped topic