Semiconductor device and method for fabricating the same

Patent metadata

Field	Value
Publication number	US-2022102193-A1
Application number	US-202117152390-A
Country	US
Kind code	A1
Filing date	Jan 19, 2021
Priority date	Sep 25, 2020
Publication date	Mar 31, 2022
Grant date	—

Abstract

A semiconductor device including: a trench defining an active region in a substrate; a first semiconductor liner formed over the trench; a second semiconductor liner formed over the first semiconductor liner; and a device isolation layer formed over the second semiconductor liner and filling the trench. Disclosed is also a method for fabricating a semiconductor device, the method including: forming a trench defining an active region in a substrate; forming a plurality of semiconductor liners over the trench; performing pretreatment before forming each of the semiconductor liners; and performing post-treatment after forming each of the semiconductor liners.

First claim

What is claimed is:

1 . A method for fabricating a semiconductor device, the method comprising:
forming a trench defining an active region in a substrate; forming a plurality of semiconductor liners over the trench; performing pretreatment before forming each of the semiconductor liners; and performing post-treatment after forming each of the semiconductor liners.

2 . The method of claim 1 , wherein the performing of the pretreatment comprises:
replacing a contaminant, generated before forming each of the semiconductor liners, with a sacrificial material; and performing heat treatment to remove the sacrificial material.

3 . The method of claim 2 , wherein the replacing of the contaminant with the sacrificial material is performed using a reactive gas having reactivity with the contaminant.

4 . The method of claim 3 , wherein the reactive gas is formed using ammonia (NH 3 ) gas, nitrogen trifluoride (NF 3 ) gas and hydrogen (H 2 ) gas.

5 . The method of claim 2 , wherein
the contaminant comprises silicon oxide, and the sacrificial material comprises ammonium hexafluorosilicate ((NH 4 ) 2 SiF 6 ).

6 . The method of claim 1 , wherein the post-treatment is performed at a higher temperature than the pretreatment.

7 . The method of claim 1 , wherein the post-treatment is performed through an annealing process or a rapid thermal process (RTP).

8 . The method of claim 1 , wherein the post-treatment is performed under a gas atmosphere containing one of nitrogen (N 2 ) and hydrogen (H 2 ).

9 . The method of claim 1 , further comprising cleaning each of the semiconductor liners, before the performing of the post-treatment.

10 . The method of claim 1 , wherein the plurality of semiconductor liners are formed by stacking polysilicon (poly-Si).

11 . The method of claim 1 , wherein the pretreatment and the forming of the semiconductor liners are performed in situ.

12 . The method of claim 1 , wherein the post-treatment is performed in one of a single equipment and a furnace equipment.

13 . A method for fabricating a semiconductor device, the method comprising:
forming a trench defining an active region in a substrate; replacing a native oxide formed on the trench with a solid salt; sublimating the solid salt to expose a surface of the trench; forming a first polysilicon liner over the trench; performing post-treatment to remove a contaminant formed on the first polysilicon liner; replacing a native oxide formed on the first polysilicon liner with a solid salt; sublimating the solid salt to expose a surface of the first polysilicon liner; forming a second polysilicon liner over the first polysilicon liner; and forming a device isolation layer filling the trench over the second polysilicon liner.

14 . The method of claim 13 , wherein the replacing of the native oxide with the solid salt is performed using a reactive gas having reactivity with the native oxide.

15 . The method of claim 14 , wherein the reactive gas is formed using ammonia (NH 3 ) gas, nitrogen trifluoride (NF 3 ) gas and hydrogen (H 2 ) gas.

16 . The method of claim 13 , wherein the solid salt comprises ammonium hexafluorosilicate ((NH 4 ) 2 SiF 6 ).

17 . The method of claim 13 , wherein the post-treatment is performed at a higher temperature than the sublimating of the solid salt.

18 . The method of claim 13 , wherein the post-treatment is performed through an annealing process or a rapid thermal process (RTP).

19 . The method of claim 13 , wherein the post-treatment is performed under a gas atmosphere containing one of nitrogen (N 2 ) and hydrogen (H 2 ).

20 . The method of claim 13 , further comprising cleaning the first polysilicon liner, before the performing of the post-treatment.

21 . The method of claim 13 , wherein the post-treatment is performed in one of a single equipment and a furnace equipment.

Assignees

• Sk Hynix Inc

Inventors

• Kim Jin Woong

Classifications

• H10P14/3602

  In-situ cleaning · CPC title

• H10P14/3248

  consisting of two layers · CPC title

• H10P14/3211

  Silicon, silicon germanium or germanium · CPC title

• H10P14/38

  characterised by treatments done after the formation of the materials · CPC title

• H10W10/0143

  comprising concurrently refilling multiple trenches having different shapes or dimensions · CPC title