Ozone vapor clean method

• US 7,157,351 B2
• Filed: 05/20/2004
• Issued: 01/02/2007
• Est. Priority Date: 05/20/2004
• Status: Expired due to Fees

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Kao, Jung-Hui, Cheng, Chung-Long, Thei, Kong-Beng
• Primary Examiner(s): Trinh; Michael
• Assistant Examiner(s): Novacek; Christy
• Application Number:
  US10/850,747
• Publication Number:
  US 20050260827A1
• Time in Patent Office: 957 Days
• Field of Search: 438/424, 438/435, 438/436, 438/437, 438/706, 438/745
• US Class Current: 438/435
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02238 silicon in uncombined form, i.e. pure silicon
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/02307 treatment by exposure to a liquid
• CPC Class Codes: H01L 21/31662 of silicon in uncombined form
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264

Abstract

A method for cleaning and forming an oxide film on a surface, particularly a silicon surface. The surface is initially cleaned and then exposed to ozone vapor, which forms the oxide film on the surface. The method is particularly useful for forming a pre-liner oxide film on trench surfaces in the fabrication of STI (shallow trench isolation) structures.

Claims

1. A method of forming a uniform thickness oxide film on a surface, comprising the steps of:

providing an ozone vapor by mixing water vapor with ozone;

cleaning said surface; and

then contacting said surface with said ozone vapor to form a first oxide film on said surface;

then, forming a second oxide film on said first oxide film.

2. The method of claim 1 wherein said surface comprises silicon.

3. The method of claim 2 wherein said providing an ozone vapor comprises the steps of providing water vapor, providing ozone, and preparing said ozone vapor by mixing said water vapor with said ozone.

4. The method of claim 1 wherein said cleaning said surface comprises the steps of providing a cleaning solution, exposing said surface to said cleaning solution, providing de-ionized water, and rinsing said surface with said de-ionized water.

5. The method of claim 4 wherein said providing an ozone vapor comprises the steps of providing water vapor, providing ozone, and preparing said ozone vapor by mixing said water vapor with said ozone.

6. The method of claim 4 wherein said surface comprises silicon.

7. The method of claim 6 wherein said providing an ozone vapor comprises the steps of providing water vapor, providing ozone, and preparing said ozone vapor by mixing said water vapor with said ozone.

8. A method of forming on trench surfaces in a substrate, comprising the steps of:

exposing said trench surfaces by etching a trench in said substrate;

providing an ozone vapor;

cleaning said trench surfaces; and

then contacting said trench surfaces with said ozone vapor to form a pre-liner oxide film;

then thermally growing an oxide liner on said pre-liner oxide film.

9. The method of claim 8 wherein said providing an ozone vapor comprises the steps of providing water vapor, providing ozone, and preparing said ozone vapor by mixing said water vapor with said ozone.

10. The method of claim 8 wherein said substrate comprises silicon.

11. The method of claim 10 wherein said providing an ozone vapor comprises the steps of providing water vapor, providing ozone, and preparing said ozone vapor by mixing said water vapor with said ozone.

12. The method of claim 8 wherein said cleaning said trench surfaces comprises the steps of exposing said trench surfaces to hydrogen fluoride, rinsing said trench surfaces, exposing said trench surfaces to an ammonia-hydrogen peroxide mixture, rinsing said trench surfaces, exposing said trench surfaces to a hydrochloric acid-hydrogen peroxide mixture, and rinsing said trench surfaces, respectively.

13. The method of claim 12 wherein said providing an ozone vapor comprises the steps of providing water vapor, providing ozone, and preparing said ozone vapor by mixing said water vapor with said ozone.

14. The method of claim 12 wherein said substrate comprises silicon.

15. The method of claim 14 wherein said providing an ozone vapor comprises the steps of providing water vapor, providing ozone, and preparing said ozone vapor by mixing said water vapor with said ozone.

16. A method of fabricating a shallow trench isolation structure, comprising the steps of:

etching a trench having trench surfaces in said substrate;

providing an ozone vapor by mixing water vapor with ozone;

cleaning said trench surfaces;

then providing a pre-liner oxide film on said trench surfaces by contacting said trench surfaces with said ozone vapor;

then providing a liner oxide layer on said pre-liner oxide film; and

providing a trench oxide on said liner oxide layer in said trench.

17. The method of claim 16 wherein said substrate comprises silicon.

18. The method of claim 16 wherein said cleaning said trench surfaces comprises the steps of exposing said trench surfaces to hydrogen fluoride, rinsing said trench surfaces, exposing said trench surfaces to an ammonia-hydrogen peroxide mixture, rinsing said trench surfaces, exposing said trench surfaces to a hydrochloric acid-hydrogen peroxide mixture, and rinsing said trench surfaces, respectively.