Method of plasma etching a substrate

• US 4,357,369 A
• Filed: 11/10/1981
• Issued: 11/02/1982
• Est. Priority Date: 11/10/1981
• Status: Expired due to Term

• Current Assignee: Intersil Corporation (Renesas Electronics Corporation)
• Original Assignee: RCA Corporation
• Inventors: Kilichowski, Kurt B., Pampalone, Thomas R.
• Primary Examiner(s): Powell, William A.
• Application Number:
  US06/320,016
• Time in Patent Office: 357 Days
• Field of Search: 156/643, 156/644, 156/646, 156/659.1, 156/668, 156/904, 427/43.1, 427/88, 427/89, 427/38, 427/39, 427/90, 427/40, 427/41, 430/296, 430/313, 430/317, 252/79.1, 204/192 E
• US Class Current: 216/18
• CPC Class Codes: C23F 4/00 Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
• CPC Class Codes: G03F 7/0758 with silicon- containing groups in the side chains
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: Y10S 438/949 Energy beam treating radiation resist on semiconductor

Abstract

A method of selectively removing a portion of a layer of material on a substrate by oxygen plasma etching utilizing a mask of a resist material comprising a poly(silane sulfone) copolymer.

Claims

1. In a method of selectively removing portions of a layer of material from a surface of a substrate by oxygen plasma etching which comprises forming on the surface of said layer a predetermined pattern of a resist material resistant to oxygen plasma etching and etching that portions of said layer not covered by said resist material, the improvement which comprises using as said resist material a copolymer having repeating units represented by the formula ##STR2## wherein R is alkyl and n is an integer.

2. A method in accordance with claim 1, wherein R is lower alkyl.

3. A method in accordance with claim 2, wherein R is methyl.

4. A method in accordance with claim 1, wherein said predetermined pattern of resist material is formed by coating said layer with a solution of said copolymer in a suitable solvent, drying said coating to form a film, irradiating selected portions of said film and developing the irradiated portions of the film with a suitable developer.

5. A method in accordance with claim 4, wherein said film is irradiated with an electron beam.

6. A method in accordance with claim 4, wherein said film is irradiated with a modulated electron beam.

7. A method in accordance with claim 4, wherein said film is baked prior to irradiation.

8. A method of forming an assembly comprising a substrate having thereon two layers of aluminum separated by a layer of insulating dielectric material wherein the layer of insulating dielectric material has vias in which there is contact between said layers of aluminum comprising:

(a) forming a first layer of aluminum on said substrate;

(b) forming a layer of insulating dielectric material on said first aluminum layer;

(c) forming a pattern of a resist material on said insulating dielectric layer, said resist material comprising a copolymer having repeating units represented by the formula ##STR3## wherein R is alkyl and n is an integer;

(d) removing the portions of said insulating layer not protected by said resist material with oxygen plasma etch thereby forming vias in said insulating layer;

(e) removing said resist material from the surface of said insulating layer; and

(f) forming a second layer of aluminum thereover so that there is contact between said aluminum layers in said vias.

9. A method in accordance with claim 8, wherein said insulating dielectric layer is polyimide.

10. A method in accordance with claim 8, wherein R is lower alkyl.

11. A method in accordance with claim 10, wherein R is methyl.