Remote plasma generation process using a two-stage showerhead

• US 4,904,621 A
• Filed: 07/16/1987
• Issued: 02/27/1990
• Est. Priority Date: 07/16/1987
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Loewenstein, Lee M., Davis, Cecil J.
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): Pawlikowski, Beverly A.
• Application Number:
  US07/074,371
• Time in Patent Office: 957 Days
• Field of Search: 427/53.1, 427/38, 427/39, 156/643, 156/646, 156/657, 156/656, 422/199, 118/728, 118/50.1, 118/620, 437/225
• US Class Current: 134/1.2
• CPC Class Codes: G03F 7/427 using plasma means only
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/67017 Apparatus for fluid treatment H01L21/67126, H01L21/6715 take precedence

Abstract

A processing apparatus and method for performing a descum process (i.e. a process for removal of polymers and other organic residues) which uses a remote plasma, supplied through a distributor which includes a two-stage showerhead, to achieve improved results.

Claims

1. A method of treating a semiconductor wafer comprising:

(a) transferring a wafer into a process vacuum chamber;

(b) applying a pressure to said chamber less than ambient to maintain said chamber at less than ambient;

(c) heating said wafer to an appropriate temperature;

(d) providing an appropriate gas to a plasma generating module separated from said chamber and producing a remote plasma;

(e) flowing said plasma sequentially through both stages of a two-stage showerhead, wherein each stage includes a baffle having a plurality of holes measuring 0.1-0.25 inch, and none of the holes in one stage is aligned with a hole of the other stage; and

(f) flowing the gas over said wafer disposed within said chamber.

3. The method as set forth in claim 1 including the step of directing said plasma over a baffle toward said showerhead.

2. A method of descumming a wafer comprising:

(a) transferring a wafer into a process vacuum chamber;

(b) applying a pressure to said chamber less than ambient to maintain said chamber at less than ambient;

(c) heating said wafer to an appropriate temperature;

(d) providing one gas from the group consisting of hydrogen, nitrous oxide, carbon tetraflouride, hydrochloric, hydrobromic or CHF₃ to a plasma generating module separated from said chamber and producing a remote plasma;

(e) flowing said plasma sequentially through both stages of a two-stage showerhead, wherein each stage includes a baffle having a plurality of holes measuring 0.1-0.25 inch, and none of the holes in one stage is aligned with a hole of the other stage; and

(f) flowing the gas over the said wafer disposal within said chamber.

4. A method of descumming a wafer comprising;

(a) disposing said wafer into a process chamber at low pressure;

(b) heating said wafer to an appropriate temperature;

(c) generating a remote plasma; and

(d) introducing said plasma sequentially through both stages of a two-stage showerhead into said chamber to a face of said water;

wherein each stage includes a baffle having a plurality of holes measuring 0.1-0.25 inch, and none of the holes in one stage is aligned with a hole of the other stage.

5. A method of descumming a wafer comprising:

(a) disposing said wafer into a process chamber;

(b) heating said wafer to an appropriate temperature;

(c) generating at least free radicals from at least one gas taken from the group consisting of hydrogen, nitrous oxide, carbon tetraflouride, hydrochloric, hydrobromic or CHF₃ in a chamber remote and in fluid communication with said process chamber; and

(d) introducing said at least free radicals sequentially through both stages of a showerhead into said process chamber and to a face of said wafer;

wherein each stage includes a baffle having a plurality of holes measuring 0.1-0.25 inch, and none of the holes in one stage is aligned with a hole of the other stage.

6. The method as set forth in claim 5 including the step of directing said plasma over a baffle toward said showerhead.