Browse Prior Art Database

Dry Etch Single Via Process

IP.com Disclosure Number: IPCOM000042058D
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Marmillion, NP: AUTHOR [+2]

Abstract

A dry etch single via process is disclosed for forming tapered via holes through polyimide-silicon nitride layers. By using dry etch as well as processing a silicon rebake step, the resulting via hole geometry can be tightly controlled. The process steps are as follows: (1) Depositing a silicon nitride (Si2N4) layer upon a substrate; (2) Spin-coating an adhesive layer onto the nitride layer; (3) Depositing a layer of polyimide onto the adhesive layer; (4) Baking and curing the polyimide layer; (5) Applying a photoresist; (6) Aligning, exposing and developing the portions of the polyimide not covered by the resist; (7) Rebaking the polyimide; (8) Dry etching the polyimide (e.g., reactive ion etch in an oxygen atmosphere); (9) Dry etching the Si3N4 (e.g.

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Dry Etch Single Via Process

A dry etch single via process is disclosed for forming tapered via holes through polyimide-silicon nitride layers. By using dry etch as well as processing a silicon rebake step, the resulting via hole geometry can be tightly controlled. The process steps are as follows: (1) Depositing a silicon nitride (Si2N4) layer upon a substrate; (2) Spin-coating an adhesive layer onto the nitride layer; (3) Depositing a layer of polyimide onto the adhesive layer; (4) Baking and curing the polyimide layer; (5) Applying a photoresist; (6) Aligning, exposing and developing the portions of the polyimide not covered by the resist; (7) Rebaking the polyimide;
(8) Dry etching the polyimide (e.g., reactive ion etch in an oxygen atmosphere);
(9) Dry etching the Si3N4 (e.g., reactive ion etch in a non-oxygen atmosphere); and (10) Dry photoresist strip processing the layers. The above-described process will reduce the thickness of the deposited polyimide layer by approximately 40%. The rebaking step prior to the dry etch of the polyimide results in tighter control of the slope of the via holes. In conventional processes, the use of wet etch steps prevents the use of this rebaking step. Further, since the foregoing process involves dry etching only, it can be readily adapted for use in the manufacture of other products.

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