Method for repairing damages to sidewalls of an ultra-low dielectric constant film

Patent metadata

Field	Value
Publication number	US-9337017-B2
Application number	US-201414758307-A
Country	US
Kind code	B2
Filing date	Aug 11, 2014
Priority date	Oct 30, 2013
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A method for repairing damages to sidewalls of an ultra-low dielectric constant film is disclosed by the present invention comprises the following steps: depositing an ultra-low dielectric constant film on an semiconductor substrate; dry-etching the ultra-low dielectric constant film to form a sidewall structure thereof; performing wet cleaning by using a chemical agent containing an unsaturated hydrocarbon having —O—C(Re)x; and performing ultraviolet curing. The present invention can restore pores size and porosity of the ultra-low dielectric constant film, and to keep effective dielectric constant to a minimum.

First claim

The invention claimed is:

1. A method for repairing damages to sidewalls of an ultra-low dielectric constant film comprises the following steps:
step S 01 : depositing an ultra-low dielectric constant film on a semiconductor substrate, wherein the ultra-low dielectric constant film is a carbon-doped porous silicon oxide film;
step S 02 : dry-etching the ultra-low dielectric constant film to form a sidewall structure in the ultra-low dielectric constant film, wherein Si—C bonds of the carbon-doped porous silicon oxide film at the sidewall structure are broken during the dry-etching process;
step S 03 : performing wet cleaning by using a chemical agent containing an unsaturated hydrocarbon having —O—C(Re)x; the unsaturated hydrocarbon having —O—C(Re)x replaces C of the broken Si—C bonds and combines with Si of the broken Si—C bonds to form Si—O—C(Re)x, wherein the C(Re)x is a molecular formula of an unsaturated hydrocarbon having —CH 3 ; and
step S 04 : performing ultraviolet curing to break O—C bonds of the Si—O—C(Re)x, so as to form an annular SixOy(CH 3 )z compound having a backbone made of Si—O—Si, wherein x, y and z are all positive integers.

2. The method according to claim 1 , wherein temperature range for wet cleaning is from 20° C. to 40° C. and time range for wet cleaning is from 15 seconds to 80 seconds.

3. The method according to claim 1 , temperature range for ultraviolet curing is from 380° C. to 500° C. and time range for ultraviolet curing is from 10 seconds to 25 seconds.

4. The method according to claim 1 , wherein the ultraviolet curing is performed in a hydrogen gas environment, and flux of the hydrogen gas is from 80 sccm to 120 sccm.

5. The method according to claim 1 , wherein the ultra-low dielectric constant film is formed by a plasma enhanced chemical vapor deposition process.

6. The method according to claim 5 , wherein reactant gases of the plasma enhanced chemical vapor deposition process are diethoxymethylsilane and oxygen, chamber temperature range is from 350° C. to 480° C. and direct current power range is from 350 watts to 600 watts.

7. The method according to claim 1 , wherein the sidewall structure is the sidewalls of vias and trenches of damascene structure.

Assignees

• Zeng Shaohai
• Zuo Qingyun
• Li Ming
• Shanghai Ic R&D Ct Co Ltd

Inventors

• Zeng Shaohai
• Zuo Qingyun
• Li Ming

Classifications

• H10P14/6922

  the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC · CPC title

• H10P14/6538

  by exposure to UV light · CPC title

• H10P14/665

  Porous materials · CPC title

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H10P70/234

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