ETCHING METHOD, ETCHING LIQUID AND ETCHING LIQUID KIT TO BE USED IN SAID METHOD, AND SEMICONDUCTOR SUBSTRATE PRODUCT MANUFACTURING METHOD

• US 20160056054A1
• Filed: 10/30/2015
• Published: 02/25/2016
• Est. Priority Date: 05/02/2013
• Status: Abandoned Application

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: TAKAHASHI, Satomi, KAMIMURA, Tetsuya, KOYAMA, Akiko, MIZUTANI, Atsushi, SUGISHIMA, Yasuo, MURAYAMA, Satoru
• Application Number:
  US14/927,798
• Publication Number:
  US 20160056054A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C23F 1/26 for etching refractory metals
• CPC Class Codes: C23F 1/28 for etching iron group metals
• CPC Class Codes: C23F 1/30 for etching other metallic material
• CPC Class Codes: C23F 1/44 Compositions for etching metallic material from a metallic material substrate of different composition
• CPC Class Codes: H01L 21/02068 during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
• CPC Class Codes: H01L 21/28088 the final conductor layer next to the insulator being a composite, e.g. TiN
• CPC Class Codes: H01L 21/28518 the conductive layers comprising silicides H01L21/28537 takes precedence
• CPC Class Codes: H01L 21/32134 by liquid etching only
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 21/823842 gate conductors with different gate conductor materials or different gate conductor implants, e.g. dual gate structures
• CPC Class Codes: H01L 29/4966 the conductor material next to the insulator being a composite material, e.g. organic material, TiN, MoSi2 H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/665 using self aligned silicidation, i.e. salicide formation of conductive layers comprising silicides H01L21/28518
• CPC Class Codes: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate
• CPC Class Codes: H01L 29/66575 where the source and drain or source and drain extensions are self-aligned to the sides of the gate H01L29/66606 takes precedence

Abstract

There is provided an etching method of a semiconductor substrate that includes a first layer containing germanium (Ge) and a second layer containing at least one metal element selected from nickel platinum (NiPt), titanium (Ti), nickel (Ni), and cobalt (Co), the method including: bringing an etching liquid which contains a specific acid compound into contact with the second layer and selectively removing the second layer.

Claims

1. An etching method of a semiconductor substrate that includes a first layer containing germanium and a second layer containing at least one metal selected from nickel platinum, titanium, nickel, and cobalt, the method comprising:

bringing an etching liquid which contains the following acid compounds into contact with the second layer and selectively removing the second layer.

Acid compounds;

at least one compound selected from halogen acid and a salt thereof;

hexafluorosilicic acid and a salt thereof;

tetrafluoroboric acid and a salt thereof, and hexafluorophosphoric acid and a salt thereof

2. The etching method according to claim 1, wherein the concentration of germanium of the first layer is 40% by mass or greater.

3. The etching method according to claim 1, further comprising:

applying a heat treatment to at least one of the first layer and the second layer before or after etching with the etching liquid.

4. The etching method according to claim 1, wherein the second layer is selectively removed with respect to the first layer and the following third layer.

Third layer:

layer containing germanium interposed between the first layer and the second layer and component metals of the second layer

5. The etching method according to claim 1,

wherein the semiconductor substrate further includes a fourth layer containing at least one of TiN, Al, AlO, W, WOx, HfOx, HfSiOx, SiN, SiOCN, and TiAlC, and

the second layer is selectively removed also with respect to the fourth layer.

6. The etching method according to claim 1, wherein, with respect to removal components of the second layer, a removal aspect I which singly uses the acid compounds and a removal aspect II which combines the acid compounds and an oxidant and uses the combination are selectively used.

7. The etching method according to claim 1, wherein the temperature of the etching liquid at the time of being brought into contact with the second layer is in the range of 10°

C. to 80°

C.

8. The etching method according to claim 1, wherein the time required for etching one substrate is in the range of 10 seconds to 300 seconds.

9. The etching method according to claim 1, further comprising:

a step of washing the semiconductor substrate with water at least before or after the etching.

10. The etching method according to claim 1,

wherein the etching liquid further contains an oxidant, and

a first liquid which does not contain the oxidant and a second liquid which contains the oxidant are divided from each other and then stored.

11. The etching method according to claim 10, wherein the first liquid and the second liquid are mixed with each other at a suitable time when the semiconductor substrate is etched.

12. The etching method according to claim 1, wherein the etching liquid further contains the following organic additive.

Organic additive:

an additive formed of an organic compound which contains a nitrogen atom, a sulfur atom, a phosphorous atom, or an oxygen atom

13. The etching method according to claim 12, wherein the organic additive is formed of a compound represented by any of the following Formulae (I) to (XIII), a phosphoric acid compound, a boron-containing acid compound, or a phosphonic acid compound.

14. The etching method according to claim 6, wherein an organic additive selected from Formulae (V) to (IX), (XI), and (XIII), a phosphoric acid compound, a boron-containing acid compound, or a phosphonic acid compound formulae is used in the case of the removal aspect I and an organic additive selected from Formula (I) to (VII), (X), and (XIII) is used in the case of the removal aspect II.

15. An etching liquid of a semiconductor substrate that includes a first layer containing germanium and a second layer containing metals other than germanium,

wherein the etching liquid is for selectively removing the second layer, and

the second layer is removed by bringing the etching liquid containing the following acid compounds and the following organic additive into contact with the second layer.

Acid compounds:

at least one compound selected from halogen acid and a salt thereof;

hexafluorosilicic acid and a salt thereof;

tetrafluoroboric acid and a salt thereof, and hexafluorophosphoric acid and a salt thereof

Organic additive;

an additive formed of an organic compound which contains a nitrogen atom, a sulfur atom, a phosphorous atom, or an oxygen atom

16. The etching liquid according to claim 15, wherein the second layer contains at least one metal selected from nickel platinum, titanium, nickel, and cobalt.

17. The etching liquid according to claim 15, wherein the concentration of the acid compound is in the range of 0.01% by mass to 10% by mass.

18. The etching liquid according to claim 15, wherein the organic additive is formed of a compound represented by any of the following Formulae (I) to (XIII), a phosphoric acid compound, a boron-containing acid compound, or a phosphonic acid compound.

19. The etching liquid according to claim 15, wherein, with respect to removal components of the second layer, a removal aspect I which singly uses the acid compounds and a removal aspect II which combines the acid compounds and an oxidant and uses the combination are selectively used.

20. The etching liquid according to claim 19, wherein an organic additive selected from Formulae (V) to (IX), (XI), and (XIII), a phosphoric acid compound, a boron-containing acid compound, or a phosphonic acid compound formulae is used in the case of the removal aspect I and an organic additive selected from Formulae (I) to (VII), (X), and (XIII) is used in the case of the removal aspect II.

21. The etching liquid according to claim 15, wherein the organic additive is formed of a compound selected from the following first group or second group.

22. The etching liquid according to claim 21,

wherein the concentration of the organic additive in the etching liquid is in the range of 50% by mass to 99% by mass when the organic additive is included in the first group, and

the concentration of the organic additive is in the range of 0.005% by mass to 10% by mass when the organic additive is included in the second group.

23. The etching liquid according to claim 15, wherein the pH of the etching liquid is 5 or less.

24. The etching liquid according to claim 15, wherein the ion concentration of Na, K, and Ca in the etching liquid is in the range of 1 ppt to 1 ppm.

25. The etching liquid according to claim 15, wherein the number of coarse particles whose average particle diameter is 0.5 μ

m or greater is 100/cm³ or less.

26. An etching liquid kit of a semiconductor substrate that includes a first layer containing germanium and a second layer containing metals other than germanium, which is for selectively removing the second layer with respect to a first layer, the etching liquid kit being formed by combining an oxidant, the following acid compounds, and the following organic additive, and comprising:

a first liquid which contains at least the oxidant; and

a second liquid which does not contain the oxidant.

Acid compounds;

at least one compound selected from halogen acid and a salt thereof;

hexafluorosilicic acid and a salt thereof;

tetrafluoroboric acid and a salt thereof, and hexafluorophosphoric acid and a salt thereof

Organic additive;

an additive formed of an organic compound which contains a nitrogen atom, a sulfur atom, a phosphorous atom, or an oxygen atom

27. A semiconductor substrate product manufacturing method that includes a first layer containing germanium, comprising:

a step of forming at least the first layer and a second layer containing at least one metal selected from nickel platinum, titanium, nickel, and cobalt on the semiconductor substrate;

a step of forming a third layer containing components of both layers between the first layer and the second layer by heating the semiconductor substrate;

a step of preparing an etching liquid containing the following acid compounds; and

a step of bringing the etching liquid into contact with the second layer and selectively removing the second layer with respect to the first layer and the third layer.

Acid compounds;

at least one compound selected from halogen acid and a salt thereof;

hexafluorosilicic acid and a salt thereof;

tetrafluoroboric acid and a salt thereof, and hexafluorophosphoric acid and a salt thereof

28. An etching liquid which is used for a semiconductor process, containing fluorine ions and an acid assistant.

29. The etching liquid according to claim 28, further containing an organic solvent and water.

30. The etching liquid according to claim 28, wherein the acid assistant is a boron-containing acid compound, a phosphoric acid compound, a phosphonic acid compound, HBr, or HCl.

31. The etching liquid according to claim 28, wherein the pKa of the acid assistant is 4 or less.

32. The etching liquid according to claim 29, wherein the organic solvent is a protonic polar organic solvent.

33. The etching liquid according to claim 28, wherein the concentration of the fluorine ion is in the range of 0.1% by mass to 20% by mass.

34. The etching liquid according to claim 29, wherein the concentration of water is in the range of 0.1% by mass to 50% by mass.

35. The etching liquid according to claim 28, wherein the concentration of the acid assistant is in the range of 0.1% by mass to 20% by mass.

36. The etching liquid according to claim 29, wherein the concentration of the organic solvent is in the range of 50% by mass to 98% by mass.

37. The etching liquid according to claim 28, further containing a carboxylic acid compound.

38. The etching liquid according to claim 28, which is used for a semiconductor substrate that includes a third layer containing silicon or silicide of germanium and a second layer containing metals other than germanium.

39. The etching liquid according to claim 38, wherein the second layer is a layer containing titanium.

40. An etching method, wherein an etching liquid containing fluorine ions and an acid assistant is used for a semiconductor substrate.

41. The etching method according to claim 40, which is used for a semiconductor substrate that includes a third layer containing silicon or silicide of germanium and a second layer containing metals other than germanium.

42. The etching method according to claim 40, wherein the second layer is a layer containing titanium.

43. A semiconductor substrate product manufacturing method, wherein a semiconductor substrate product is manufactured through the etching method according to claim 40.