Controlled polymerization on plasma reactor wall

• US 20040084409A1
• Filed: 11/04/2002
• Published: 05/06/2004
• Est. Priority Date: 11/04/2002
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Lill, Thorsten B., Deshmukh, Shashank C.
• Granted Patent: US 7,122,125 B2
• Time in Patent Office: Days
• US Class Current: 216/63
• CPC Class Codes: H01J 37/32009 Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources plasma generation in general H05H1/24
• CPC Class Codes: H01J 37/32532 Electrodes
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 21/32139 using masks
• CPC Class Codes: H01L 21/67069 for drying etching

Abstract

An integrated etch process, for example as used for etching an anti-reflection layer and an underlying aluminum layer, in which the chamber wall polymerization is controlled by coating polymer onto the sidewall by a plasma deposition process prior to inserting the wafer into the chamber, etching the structure, and after removing the wafer from the chamber, plasma cleaning the polymer from the chamber wall. The process is process is particularly useful when the etching is performed in a multi-step process and the polymer is used for passivating the etched structure, for example, a sidewall in an etched structure and in which the first etching step deposits polymer and the second etching step removes polymer. The controlled polymerization eliminates interactions of the etching with the chamber wall material, produces repeatable results between wafers, and eliminates in the etching plasma instabilities associated with changing wall conditions.

Claims

11-1. The process of claim 1, wherein a dummy substrate is disposed on said pedestal during said depositing and cleaning steps.

12. An integrated silicon etch process, comprising the steps performed in a plasma reactor for each of a plurality of sequentially processed production wafers:

depositing from a plasma of a first gas mixture including a carbon-containing gas a first second polymeric coating onto a part of said reactor;

a first etching step of etching a first layer overlying a silicon layer in one of said production wafers with a plasma of a second gas mixture, said first etching step causing a second polymeric coating to deposit on said part;

a second etching step of etching said silicon layer with a plasma of a third gas mixture comprising bromine; and

cleaning said part with a plasma of a fourth gas mixture comprising oxygen.

13. The process of claim 12, wherein said one of said production wafers is loaded into said reactor between said depositing and first etching steps and is removed from said reactor between said second etching and cleaning steps.

14. The process of claim 12, wherein said carbon-containing gas comprises a fluorocarbon gas.

15. The process of claim 14, wherein said first gas mixture further comprises a fluorine-scavenging gas.

16. The process of claim 12, wherein said first layer is an anti-reflection coating.

17. The process of claim 16, wherein said first layer comprises an organic material, said second gas mixture comprises hydrogen bromide and oxygen, and said third gas to mixture comprises hydrogen bromide, chlorine gas, and oxygen gas.

18. The process of claim 16, wherein said first layer comprises silicon oxynitride, said second gas mixture comprises a fluorocarbon, and said third gas mixture comprises hydrogen bromide, chlorine gas, and oxygen gas.

19. An integrated etch process including a process cycle performed for each of a plurality of production substrates loaded onto a pedestal in process cycle comprising the sequentially performed steps of:

depositing a polymeric coating onto an interior wall while no production substrate is disposed on said pedestal;

loading one of said production substrates onto said pedestal;

etching said one production substrate with a plasma process;

unloading said one production substrate from pedestal; and

cleaning any polymer from said interior wall with a plasma process while no production substrate is disposed on said pedestal.

20. The process of claim 19, wherein a dummy substrate is disposed on said pedestal during said depositing and cleaning steps.

21. The process of claim 19, wherein no substrate is disposed on said pedestal during said depositing and cleaning steps.

22. The process of claim 19, wherein said plasma process of said cleaning step includes a plasma of oxygen gas.