Method for non mass selected ion implant profile control

• US 6,274,459 B1
• Filed: 02/16/1999
• Issued: 08/14/2001
• Est. Priority Date: 02/17/1998
• Status: Expired due to Term

• Current Assignee: Silicon Genesis
• Original Assignee: Silicon Genesis
• Inventors: Chan, Chung
• Primary Examiner(s): Bowers, Charles
• Assistant Examiner(s): Smoot, Stephen W.
• Application Number:
  US09/250,696
• Time in Patent Office: 910 Days
• Field of Search: 438/513, 438/514, 438/423, 438/455, 438/458, 438/795, 438/798, 438/162, 438/692, 438/475, 438/473, 438/474, 118/723.ER
• US Class Current: 438/475
• CPC Class Codes: H01J 37/32412 Plasma immersion ion implantation
• CPC Class Codes: H01L 21/2236 from or into a plasma phase
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond

Abstract

A method for implanting a substrate face using a plasma processing apparatus (10). The method includes providing a substrate (e.g., wafer, panel) (22) on a face of a susceptor. The substrate has an exposed face, which has a substrate diameter that extends from a first edge of the substrate to a second edge of the substrate across a length of the substrate. The method also includes forming a plasma sheath (26) around the face of the substrate. The plasma sheath has a dark space distance “D” that extends in a normal manner from the exposed face to an edge of the plasma sheath. The dark space distance and the substrate diameter comprise a ratio between the dark space distance and the substrate diameter. The ratio is about one half and less, which provides a substantially uniform implant.

Claims

1. A method for implanting a substrate face using a plasma processing apparatus, said method comprising:

providing a substrate on a face of a susceptor, said face of said susceptor comprising a portion that extends outside of a diameter of said substrate, said substrate having an exposed face, said exposed face comprising a substrate diameter that extends from a first edge of said substrate to a second edge of said substrate across a length of said substrate;

forming a plasma sheath comprising hydrogen ions around said face of said substrate, said plasma sheath comprising a dark space distance that extends in a normal manner from said exposed face to an edge of said plasma sheath; and

applying a voltage potential between said plasma sheath and said substrate to accelerate said hydrogen ions through said exposed face to a selected depth;

wherein said dark space distance and said substrate diameter comprise a ratio between said dark space distance and said substrate diameter, said ratio being at about one half and less within substantially a first portion of said exposed face;

wherein said substrate is maintained in an environment at a pressure of about 1 millitorr and less to reduce a possibility of a collision between at least one of said hydrogen ions and a neutral; and

wherein said substrate is maintained at a temperature of about 205°

Celsius and less to prevent a possibility of said implanted hydrogen ions from diffusing out of said substrate.

2. The method of claim 1 wherein said substrate is selected from a wafer, a silicon wafer, or a flat panel display.

3. The method of claim 1 wherein said substrate comprises a silicon wafer.

4. The method of claim 1 wherein said length is a widest length of said substrate.

5. The method of claim 1 wherein said portion is about twenty five percent or greater of said substrate diameter.

6. The method of claim 1 wherein said substrate is maintained in an environment of about one half a millitorr and less, but greater than about one fifth of a millitorr.

7. The method of claim 1 wherein said plasma sheath comprises a plasma density of at least 10¹⁰ ions/cm³ of hydrogen bearing particles.

8. The method of claim 1 wherein said plasma sheath comprises a plasma density of at least 10¹¹ ions/cm³ of hydrogen bearing particles.