Browse Prior Art Database

Profile Control in Plasma Etching of Sio2

IP.com Disclosure Number: IPCOM000062740D
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Ng, HY: AUTHOR

Abstract

Sloped profile SiO2 contact windows and nitride vias are necessary in order to achieve good step coverage and minimize crack vacuum deposited metal films. One of the most promising ways of achieving sloped walls is by controlled photoresist erosion. If the photoresist has a slightly rounded profile before etching, the etch rate of the photoresist with respect to the material being etched can be adjusted so that the underlying layer has sloped walls. The disclosed technique allows for controlled photoresist erosion prior to contact hole etching.

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Profile Control in Plasma Etching of Sio2

Sloped profile SiO2 contact windows and nitride vias are necessary in order to achieve good step coverage and minimize crack vacuum deposited metal films. One of the most promising ways of achieving sloped walls is by controlled photoresist erosion. If the photoresist has a slightly rounded profile before etching, the etch rate of the photoresist with respect to the material being etched can be adjusted so that the underlying layer has sloped walls. The disclosed technique allows for controlled photoresist erosion prior to contact hole etching.

Following photoresist deposition, masking and developing, the photoresist is precleaned by dipping in buffered hydrofluoric acid (BHF). After a short BHF dip, the resist is reflowed, resulting in a very high uniform profile. The normal etching of the SiO2 layer follows.

The addition of the precleaning BHF dip provides for an improved resist profile which is necessary to obtain line width control.

Disclosed anonymously.

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