Etching method and method of fabricating a semiconductor device using the same

Patent metadata

Field	Value
Publication number	US-9972696-B2
Application number	US-201615229930-A
Country	US
Kind code	B2
Filing date	Aug 5, 2016
Priority date	Sep 21, 2015
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The present disclosure relates to an etchant, a method of making an etchant, an etching method and a method of fabricating a semiconductor device using the same. The etching method includes supplying an etchant on an etch-target layer to etch the etch-target layer in a wet etch manner. The etchant contains a basic compound and a sugar alcohol, and the basic compound contains ammonium hydroxide or tetraalkyl ammonium hydroxide. In the etchant, the sugar alcohol has 0.1 to 10 parts by weight for every 100 parts by weight of the basic compound.

First claim

What is claimed is:

1. A method of manufacturing a semiconductor device, comprising:
supplying an etchant on an etch-target layer on a semiconductor substrate to etch the etch-target layer with a wet etch process,
wherein the etchant comprises a basic compound and a sugar alcohol,
wherein the basic compound comprises ammonium hydroxide or tetraalkyl ammonium hydroxide,
wherein, in the etchant, the sugar alcohol has 0.1 to 10 parts by weight for every 100 parts by weight of the basic compound, and
wherein the etchant further comprises a compound that has 0.1 to 10 parts by weight for every 100 parts by weight of the basic compound and is represented by the following chemical formula 1:

wherein R 1 is selected from the group consisting of a C1-C10 alkyl group and a C6-C8 aryl group, and
wherein each of R 2 and R 3 is independently selected from the group consisting of hydrogen, a C1-C10 alkyl group, and a C6-C8 aryl group.

2. The method of claim 1 , wherein the etch-target layer is polysilicon.

3. The method of claim 1 , wherein the sugar alcohol is at least one selected from the group consisting of sorbitol, glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, galactitol, fucitol, iditol, inositol, volemitol, maltitol, lactitol, maltotritol, maltotetraitol, and polyglycitol.

4. The method of claim 1 , wherein the etchant is prepared by:
mixing the basic compound with the sugar alcohol to prepare an etchant mixture; and
mixing the etchant mixture with water of 60-100° C.

5. A method of fabricating a semiconductor device, comprising:
forming a device isolation layer on a substrate to define an active pattern;
forming a sacrificial gate pattern that crosses over the active pattern; and
replacing the sacrificial gate pattern with a gate electrode,
wherein the replacing of the sacrificial gate pattern with the gate electrode comprises supplying an etchant on the sacrificial gate pattern to etch the sacrificial gate pattern using a wet etch process,
wherein the etchant comprises a basic compound, a sugar alcohol, and a compound represented by the following chemical formula 1, and
wherein the basic compound comprises ammonium hydroxide or tetraalkyl ammonium hydroxide, and
wherein the compound of the etchant is represented by the following chemical formula 1:

where R 1 is selected from the group consisting of a C1-C10 alkyl group and a C6-C8 aryl group, and each of R 2 and R 3 is independently selected from the group consisting of hydrogen, a C1-C10 alkyl group, and a C6-C8 aryl group.

6. The method of claim 5 , wherein the sacrificial gate pattern comprises polysilicon.

7. The method of claim 5 , wherein, in the etchant, for every 100 parts by weight of the basic compound, the sugar alcohol has 0.1 to 10 parts by weight and the compound of the chemical formula 1 has 0.1 to 10 parts by weight.

8. The method of claim 5 , wherein the etchant has a pH value ranging from 12 to 14.

9. The method of claim 5 , wherein the tetraalkyl ammonium hydroxide is at least one selected from the group consisting of Tetramethylammonium Hydroxide (TMAH), Tetraethylammonium Hydroxide (TEAH), and Tetrabuthylammonium Hydroxide (TBAH).

10. The method of claim 5 , wherein the sugar alcohol is at least one selected from the group consisting of sorbitol, glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, galactitol, fucitol, iditol, inositol, volemitol, maltitol, lactitol, maltotritol, maltotetraitol, and polyglycitol.

11. The method of claim 5 , wherein in the chemical formula 1, R 1 is the C1-C10 alkyl group and each of R 2 and R 3 is hydrogen.

12. The method of claim 5 , further comprising:
forming a pair of spacers to cover both sidewalls of the sacrificial gate pattern; and
covering the active pattern and the spacers with an interlayer insulating layer,
wherein the replacing of the sacrificial gate pattern with the gate electrode further comprises:
performing a wet etching process on the sacrificial gate pattern to form a gate trench defined by the spacers; and
forming a gate electrode to fill the gate trench.

13. The method of claim 12 , further comprising forming source/drain regions in portions of the active pattern at both sides of the sacrificial gate pattern, before the forming the interlayer insulating layer,
wherein the performing a wet etching process does not etch the source/drain regions.

14. The method of claim 5 , wherein the active pattern comprises an active fin protruding above a device isolation layer.

15. A method for manufacturing an etchant, comprising:
mixing a basic compound with a sugar alcohol to prepare an etchant mixture; and
mixing the etchant mixture with deionized water, wherein the deionized water is in the range of 60-100° C.,
wherein the basic compound comprises ammonium hydroxide or tetraalkyl ammonium hydroxide, and
wherein, in the etchant, the sugar alcohol has 0.1 to 10 parts by weight for every 100 parts by weight of the basic compound.

16. The method of claim 15 , wherein the sugar alcohol is at least one selected from the group consisting of sorbitol, glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, galactitol, fucitol, iditol, inositol, volemitol, maltitol, lactitol, maltotritol, maltotetraitol, and polyglycitol.

17. The method of claim 15 , wherein the etchant further comprises a compound that has 0.1 to 10 parts by weight for every 100 parts by weight of the basic compound and is represented by the following chemical formula 1:

wherein R 1 is selected from the group consisting of a C1-C10 alkyl group and a C6-C8 aryl group, and
wherein each of R 2 and R 3 is independently selected from the group consisting of hydrogen, a C1-C10 alkyl group, and a C6-C8 aryl group.

18. The method of claim 15 , wherein the etchant has a pH value ranging from 12 to 14.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Hoyoung
• Bae Sang Won
• Baek Jae-Jik
• Choi Wonsang

Classifications

• H10P50/667

  by liquid etching only · CPC title

• H10P14/416

  of highly doped semiconductor materials, e.g. polysilicon layers or amorphous silicon layers · CPC title

• H10D64/01356

  the insulator being formed after the semiconductor body, the semiconductor being a Group IV material and not being silicon, e.g. Ge, SiGe or SiGeC (H10D64/01364, H10D64/01366 take precedence) · CPC title

• H10D64/01302

  the insulator being formed after the semiconductor body, the semiconductor being silicon · CPC title

• C09K13/00

  Etching, surface-brightening or pickling compositions (for glass C03C15/00, {C03C25/66; for mortars, concrete, artificial or natural stone or ceramics C04B41/5338}; for metallic material C23F, C23G1/00, C25F1/00; {for semi-conductors H10P52/40}) · CPC title