Method for treating semiconductor wafers with corona charge and devices using corona charging

• US 6,127,289 A
• Filed: 09/05/1997
• Issued: 10/03/2000
• Est. Priority Date: 09/05/1997
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Debusk, Damon Keith
• Primary Examiner(s): Whitehead, Jr., Carl
• Assistant Examiner(s): GUERRERO, MARIA F
• Application Number:
  US08/924,268
• Time in Patent Office: 1,124 Days
• Field of Search: 438/795, 438/798, 399/174, 399/175, 399/176, 399/170, 361/221, 361/225, 361/229
• US Class Current: 438/798
• CPC Class Codes: H01L 21/326 Application of electric currents or fields, e.g. for electroforming H01L21/20 - H01L21/288 and H01L21/302 - H01L21/324 take precedence

Abstract

A method of treating the surface of a semiconductor wafer is disclosed for making the wafer resistant to particle adhesion, the method involving the application of a uniform corona charge to the wafer surface. The corona charge is deposited on the wafer using commercially available tools, and if necessary, it may be later removed by immersing the wafer in deionized water or by depositing a compensating corona charge over the wafer of opposite polarity relative to the originally-applied charge.

Claims

1. A method of treating a semiconductor wafer to provide a semiconductor wafer resistant to particle depositions, the method comprising the steps of:

(a) providing the semiconductor wafer having a surface with a surface charge potential;

(b) positioning the semiconductor wafer so that the surface is disposed adjacent a corona charging source;

(c) depositing a substantially uniform corona charge over the surface of the semiconductor wafer to modify the surface charge potential of the semiconductor wafer to define the semiconductor wafer adapted to resist particle depositions; and

(d) disposing the semiconductor wafer in an apparatus for storage or fabrication of the semiconductor wafer wherein the surface charge potential of the semiconductor wafer repels particles during the storage or fabrication, thereby reducing the need for chemical applications to cleanse the semiconductor wafer.

2. The method according to claim 1, further comprising the step of (d) removing the charge deposited on the wafer by applying a second corona charge over the surface of the wafer of opposite polarity to the substantially uniform charge applied pursuant to step (c).

3. The method according to claim 1, further comprising the step of (d) immersing the wafer in a bath of deionized water to remove the substantially uniform charge applied pursuant to step (c).

4. The method according to claim 1, wherein the step of positioning the semiconductor wafer comprises securing the wafer on a substantially horizontal plane on a vacuum chuck.

5. The method according to claim 4, wherein the step of positioning the semiconductor wafer adjacent the charging source comprises disposing a corona charging station from about one to two inches above the surface of the wafer.

6. The method according to claim 5, wherein the step of applying the substantially uniform charge involves holding the wafer stationary while passing a corona charging gun back and forth over the surface of the wafer.

7. The method according to claim 6, wherein the step of applying the substantially uniform charge involves applying a charge of positive polarity.

8. The method according to claim 6, wherein the step of applying the substantially uniform charge involves applying a charge of negative polarity.

9. The method according to claim 6, further comprising the step of measuring the contact potential difference on the surface of the wafer to determine the desired charge level.

10. A method for providing a semiconductor wafer resistant to the deposition of particles and having an improved stability, the method comprising the steps of:

(a) providing the semiconductor wafer having a surface with a surface charge potential;

(b) positioning the semiconductor wafer adjacent a corona charging source;

(c) depositing a substantially uniform corona charge over the surface of the semiconductor wafer to modify the surface charge potential of the semiconductor wafer; and

(d) storing or fabricating the semiconductor wafer wherein the semiconductor wafer repels particles during such storage or fabrication to provide the semiconductor wafer having the improved stability without use of irradiation, wafer scrubbing, or chemical cleansing processes.

11. A method for pre-treating a semiconductor wafer to provide a semiconductor wafer resistant to the deposition of particles, the method consisting essentially of the steps of:

(a) providing the semiconductor wafer having a surface adapted for use in fabricating active components of a semiconductor device;

(b) positioning the semiconductor wafer adjacent a corona charging source; and

(c) depositing a substantially uniform corona charge over the surface of the semiconductor wafer to modify the surface charge potential of the semiconductor wafer and provide the semiconductor wafer resistant to the deposition of particles, wherein the time and voltage of the corona charge results in an electrical field that is less than the electrical breakdown field of the material comprising the surface of the semiconductor wafer, whereby the active components of the semiconductor device may be deposited on the surface of the semiconductor wafer without use of irradiation, wafer scrubbing, or chemical cleansing processes.