Methods and systems for using oxidation layers to improve device surface uniformity

Patent metadata

Field	Value
Publication number	US-9449866-B2
Application number	US-201514590011-A
Country	US
Kind code	B2
Filing date	Jan 6, 2015
Priority date	Mar 24, 2014
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

The invention discloses a treatment process for a semiconductor, comprising providing a substrate, the substrate comprises silicon material; defining a trench region; removing the trench region using a plasma etching process and exposing a trench surface, the trench surface comprising surface defects; forming an oxidation layer overlaying the trench surface; removing the oxidation layer and at least a portion of the surface defects; expositing a treated trench surface, the treated trench surface being substantially free from surface defects; and forming a layer of silicon germanium material overlaying the treated trench surface. The invention further provides a semiconductor processing technique used to eliminate or reduce dislocation defect on the semiconductor device and improve device performance. In the treatment process, a substrate is subjected to at least one oxidation-deoxidation processes, where an oxidation layer is formed and then removed.

First claim

What is claimed is:

1. A method for processing a semiconductor substrate, the method comprising:
providing a substrate, the substrate comprises silicon material;
defining a trench region;
removing the trench region using a plasma etching process and exposing a trench surface, the trench surface comprising surface defects;
forming an oxidation layer overlaying the trench surface;
removing the oxidation layer and at least a portion of the surface defects;
expositing a treated trench surface, the treated trench surface being substantially free from surface defects, the surface defect comprising a polymer material; and
forming a layer of silicon germanium material overlaying the treated trench surface.

2. The method of claim 1 , wherein the silicon germanium material is substantially free from surface defects.

3. The method of claim 1 , wherein the surface defects comprise misaligned silicon material.

4. The method of claim 1 , wherein the oxidation layer is embedded with at least a portion of the surface defects.

5. The method of claim 1 , further comprising subjecting the trench surface to a plasma to form the oxidation layer.

6. The method of claim 1 , wherein the trench surface is subjected to an oxidation treatment by a plasma etching machine.

7. The method of claim 1 , wherein the forming of the oxidation layer further comprises a flow rate of oxide gas of 20 sccm-50 sccm; a source power of 300 w-500 w; a bias voltage of 0; and a treatment time of 5 s-15 s.

8. The method of claim 7 , wherein the oxide gas is oxygen.

9. The method of claim 1 , wherein removing the oxidation layer is characterized by:
a flow rate of gas of 10 sccm-50 sccm;
a source power of 200 w-400 w;
a bias voltage of 0; a removing time is 5 s-15 s;
a relative molecular mass of gas being not greater than 100; and
a carbon content being not greater than 30% in gas molecules.

10. The method of claim 9 , wherein the gas is selected from a group comprises nitrogen trifluoride, carbon tetrafluoride, fluoroform and sulfur hexafluoride.

11. The method of claim 1 , wherein the oxidation layer is having a thickness of 2 nm-8 nm.

12. The method of claim 1 , wherein the substrate is made of materials selected from a group comprises polycrystalline silicon, monocrystalline silicon and metal.

13. A method for processing a semiconductor substrate, the method comprising:
providing a substrate, the substrate comprises a silicon material;
defining a trench region;
removing the trench region using a plasma etching process and exposing a trench surface, the trench surface comprising surface defects, the surface defects comprising silicon and polymer material;
subjecting the trench surface to plurality of gaseous species to form an oxidation layer overlaying the trench surface, the oxidation layer being less than 10 nm in thickness;
removing the oxidation layer and at least a portion of the surface defects;
expositing a treated trench surface, the treated trench surface being substantially free from surface defects; and
forming a layer of silicon germanium material overlaying the treated trench surface.

14. The method of claim 13 wherein the removing the oxidation layer comprises a plasma etching process.

15. The method of claim 13 wherein the removing the oxidation layer comprises a wet etching process.

16. A method for processing a semiconductor substrate, the method comprising:
providing a substrate, the substrate comprises a silicon material;
defining a trench region;
removing the trench region using a plasma etching process and exposing a trench surface, the trench surface comprising surface defects;
forming an oxidation layer overlaying the trench surface;
removing the oxidation layer and at least a portion of the surface defects;
repeating the steps of forming and removing the oxidation layer;
expositing a treated trench surface, the treated trench surface being substantially free from surface defects;
forming a layer of silicon germanium material overlaying the treated trench surface; and
forming a drain or a source region using the layer of silicon germanium material.

Assignees

• Shanghai Huali Microelect Corp

Inventors

• Li Quanbo
• Huang Jun
• Meng Xiangguo
• Zhang Yu

Classifications

• H10P50/283

  by chemical means · CPC title

• H10P14/6319

  Formation by plasma treatments, e.g. plasma oxidation of the substrate · CPC title

• H10P14/6309

  of silicon in uncombined form, i.e. pure silicon · CPC title

• H10P14/3411

  Silicon, silicon germanium or germanium · CPC title

• H10P14/2905 Primary

  Silicon, silicon germanium or germanium · CPC title