Etching method, and method of producing semiconductor substrate product and semiconductor device using the same

Patent metadata

Field	Value
Publication number	US-9558953-B2
Application number	US-201514593150-A
Country	US
Kind code	B2
Filing date	Jan 9, 2015
Priority date	Jul 20, 2012
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

An etching method, having the step of applying an etching liquid onto a TiN-containing layer in a semiconductor substrate thereby etching the TiN-containing layer, the etching liquid comprising water, and a basic compound and an oxidizing agent in water thereof to be within the range of pH from 8.5 to 14, and the TiN-containing layer having a surface oxygen content from 0.1 mol % to 10 mol %.

First claim

The invention claimed is:

1. An etching method, comprising the steps of:
preparing an etching liquid comprising water, a basic compound, and an oxidizing agent, the etching liquid being in the range of pH from 8.5 to 14, and
applying the etching liquid onto a TiN-containing layer in a semiconductor substrate thereby etching the TiN-containing layer at an etching rate of 50 to 500 Å/min, the TiN-containing layer having a surface oxygen content from 0.1 mol % to 10 mol %,
wherein the basic compound is a compound represented by formula (I):
N(R) 4 .OH  Formula (I)

wherein R represents a substituent; and a plurality of Rs may be the same or different from each other.

2. The etching method according to claim 1 ,
wherein the basic compound is tetramethylammonium hydroxide, tetraethylammonium hydroxide, or tetrapropylammonium hydroxide.

3. The etching method according to claim 1 ,
wherein the oxidizing agent is hydrogen peroxide, ammonium persulfate, perboric acid, peracetic acid, periodic acid, perchloric acid, or a combination thereof.

4. The etching method according to claim 1 ,
wherein the semiconductor substrate has a first layer of the TiN-containing layer and a second layer containing at least one of Cu, SiO, SiN, SiOC and SiON, and an etching rate ratio of an etching rate (R1) of the first layer to an etching rate (R2) of the second layer (R1/R2) is 30 or more.

5. The etching method according to claim 1 ,
wherein the surface oxygen content of the TiN-containing layer is obtained by using etching ESCA thereby measuring a concentration profile of Ti, O, and N in the depth direction of 0 to 30 nm from the surface of the TiN-containing layer, in terms of an average of oxygen content at the depth of 5 to 10 nm thereof.

6. The etching method according to claim 1 , wherein the etching is conducted at 40° C. or higher.

7. The etching method according to claim 1 , wherein the etching is conducted by using single wafer type processing equipment.

8. The etching method according to claim 1 , comprising the steps of:
mixing a first liquid and a second liquid, thereby obtaining the etching liquid; the first liquid comprising water and a basic compound, the second liquid comprising water and an oxidizing agent; and
applying the etching liquid onto the semiconductor substrate on a timely basis.

9. The etching method according to claim 1 , wherein the etching liquid further comprises a water-soluble organic solvent.

10. A method of producing a semiconductor substrate product, comprising the step of etching the TiN-containing layer of the semiconductor substrate by the etching method according to claim 1 .

11. A method of producing a semiconductor device, producing the semiconductor device by using the semiconductor substrate product obtained by the production method according to claim 10 .

12. The etching method according to claim 1 , wherein the basic compound is tetramethylammonium hydroxide.

13. The etching method according to claim 1 , wherein the oxidizing agent is hydrogen peroxide.

14. An etching method, comprising the steps of:
preparing an etching liquid consisting essentially of water, a basic compound, and an oxidizing agent, the etching liquid being in the range of pH from 8.5 to 14,
applying the etching liquid onto a TiN-containing layer in a semiconductor substrate thereby etching the TiN-containing layer, the TiN-containing layer having a surface oxygen content from 0.1 mol % to 10 mol %,
wherein the basic compound is a compound represented by formula (I):
N(R) 4 .OH  Formula (I)

wherein R represents a substituent; and a plurality of Rs may be the same or different from each other.

15. The etching method according to claim 14 ,
wherein the basic compound is tetramethylammonium hydroxide, tetraethylammonium hydroxide, or tetrapropylammonium hydroxide.

16. The etching method according to claim 15 ,
wherein the basic compound is tetramethylammonium hydroxide.

17. The etching method according to claim 14 ,
wherein the oxidizing agent is hydrogen peroxide, ammonium persulfate, perboric acid, peracetic acid, periodic acid, perchloric acid, or a combination thereof.

18. The etching method according to claim 17 ,
wherein the oxidizing agent is hydrogen peroxide.

19. The etching method according to claim 14 ,
wherein the semiconductor substrate has a first layer of the TiN-containing layer and a second layer containing at least one of Cu, SiO, SiN, SiOC and SiON, and an etching rate ratio of an etching rate (R1) of the first layer to an etching rate (R2) of the second layer (R1/R2) is 30 or more.

20. The etching method according to claim 14 ,
wherein the surface oxygen content of the TiN-containing layer is obtained by using etching ESCA thereby measuring a concentration profile of Ti, O, and N in the depth direction of 0 to 30 nm from the surface of the TiN-containing layer, in terms of an average of oxygen content at the depth of 5 to 10 nm thereof.

21. The etching method according to claim 14 , wherein the etching is conducted at 40° C. or higher.

22. The etching method according to claim 14 , wherein the etching is conducted by using single wafer type processing equipment.

23. The etching method according to claim 14 , comprising the steps of:
mixing a first liquid and a second liquid, thereby obtaining the etching liquid; the first liquid consisting essentially of water and a basic compound, the second liquid consisting essentially of water and an oxidizing agent; and
applying the etching liquid onto the semiconductor substrate on a timely basis.

24. The etching method according to claim 14 , wherein the etching liquid further contains a water-soluble organic solvent.

25. A method of producing a semiconductor substrate product, comprising the step of etching a TiN-containing layer of a semiconductor substrate by the etching method according to claim 14 .

26. A method of producing a semiconductor device, which comprises fabricating a circuit on the semiconductor substrate product obtained by the production method according to claim 25 .

Assignees

• Fujifilm Corp

Inventors

• Muro Naotsugu
• Kamimura Tetsuya
• Inaba Tadashi
• Watanabe Takahiro
• Park Kee Young

Classifications

• H10P50/73

  using masks for insulating materials · CPC title

• H10P70/234 Primary

  the processing being the formation of vias or contact holes · CPC title

• H10P50/667

  by liquid etching only · CPC title

• H10P50/644 Primary

  Anisotropic liquid etching (H10P50/61 takes precedence) · CPC title

• H01L21/32134

  Electricity · mapped topic