Coated platen design for plasma immersion ion implantation

• US 6,217,724 B1
• Filed: 12/18/1998
• Issued: 04/17/2001
• Est. Priority Date: 02/11/1998
• Status: Expired due to Term

• Current Assignee: Silicon Genesis
• Original Assignee: Silicon General Corporation
• Inventors: Chu, Paul K., Chan, Chung
• Primary Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US09/215,094
• Time in Patent Office: 851 Days
• Field of Search: 118/723.I, 118/723.IR, 118/723.MP, 118/728, 118/733, 427/523, 427/524, 427/527, 204/192.32, 204/192.37, 204/298.32, 204/298.36, 204/298.15, 156/345
• US Class Current: 204/192.37
• CPC Class Codes: C23C 14/48 Ion implantation
• CPC Class Codes: C23C 14/50 Substrate holders
• CPC Class Codes: C23C 14/564 Means for minimising impurities in the coating chamber such as dust, moisture, residual gases
• CPC Class Codes: C23C 16/507 using external electrodes, e.g. in tunnel type reactors
• CPC Class Codes: H01J 37/32412 Plasma immersion ion implantation
• CPC Class Codes: H01J 37/32559 Protection means, e.g. coatings

Abstract

A plasma treatment system (200) for implantation with a novel susceptor with a silicon coating (203). The system (200) has a variety of elements such as a chamber, which can have a silicon coating formed thereon, in which a plasma is generated in the chamber. The system (200) also has a susceptor disposed in the chamber to support a silicon substrate. The silicon coating reduces non-silicon impurities that may attach to the silicon substrate. In a specific embodiment, the chamber has a plurality of substantially planar rf transparent windows (26) on a surface of the chamber. The system (200) also has an rf generator (66) and at least two rf sources in other embodiments.

Claims

1. A plasma immersion ion implantation (PIII) treatment system for implantation, said system comprising:

a chamber in which a plasma is generated in said chamber, said chamber having a bottom region exposed to the plasma and lined with silicon; and

a silicon coated susceptor disposed in said chamber to support a silicon substrate, said silicon coated susceptor providing fewer non-silicon bearing impurities that can be sputtered off of the susceptor during an implantation process.

2. The system of claim 1 wherein said chamber comprises a plurality of substantially planar rf transparent windows on a surface of said chamber.

3. The system of claim 1 further comprising:

an rf generator; and

at least two rf sources, each external to said vacuum chamber and each said rf source electrically connected to said rf generator and juxtaposed to a respective one of said plurality rf transparent windows, and operative to generate said plasma in the vacuum chamber;

said rf sources operative to produce a local, substantially uniform plasma proximate said substrate.

4. The system of claim 3 further comprising at least one tuning circuit, each said at least one tuning circuit electrically connected to one of said at least two rf sources.

5. The system of claim 1 wherein said silicon coated susceptor has a coating selected from polysilicon, amorphous silicon, or crystalline silicon.

6. The system of claim 5 wherein said silicon coated susceptor has a base metal selected from stainless steel or aluminum.

7. The system of claim 1 wherein said silicon substrate is a silicon bearing wafer.

8. The system of claim 1 wherein said chamber comprises a silicon coating defined on an interior region of said chamber, said silicon coating providing fewer non-silicon impurities onto said silicon substrate, said non-silicon impurities can be sputtered off of said chamber.

9. The system of claim 8 wherein said silicon coating is selected from amorphous silicon, polysilicon, or crystalline silicon.

10. The system of claim 8 wherein said chamber comprises an aluminum bearing material underlying said silicon coating.

11. The system of claim 1 wherein said system is provided in a cluster tool.

12. A method for forming a substrate, said method comprising steps of:

providing a substrate onto a silicon coated susceptor within a plasma immersion ion implantation chamber, said substrate comprising a silicon wafer with a surface, and said chamber having a bottom surface exposed to a plasma and lined with silicon;

introducing particles in a directional manner toward and through said surface of said substrate to uniformly place said ions into a selected depth across a plane of said substrate; and

sputtering silicon bearing material off of said silicon coated susceptor, said silicon bearing material being attached to said surface of said substrate.

13. The method of claim 12 wherein said silicon coated susceptor comprises a material selected from an amorphous silicon, polysilicon, or crystalline silicon.

14. The method of claim 12 wherein said silicon coated susceptor comprises a base material selected from aluminum or stainless steel.

15. The method of claim 12 wherein said substrate comprises silicon wafer.

16. The method of claim 12 wherein said chamber comprises a silicon coating defined on interior surfaces of said chamber.

17. The method of claim 16 wherein said silicon coating is selected from amorphous silicon, polysilicon, or crystalline silicon.

18. The method of claim 12 wherein said method occurs in a cluster tool.