Browse Prior Art Database

Etching of SiO Using Plasma

IP.com Disclosure Number: IPCOM000080246D
Original Publication Date: 1973-Nov-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Anderson, R: AUTHOR [+3]

Abstract

It is shown herein that Si0 can be etched using a mixture of FREON* and O(2) plasma.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 97% of the total text.

Page 1 of 1

Etching of SiO Using Plasma

It is shown herein that Si0 can be etched using a mixture of FREON* and O(2) plasma.

When films of SiO are placed into plasma of FREON (CF(4)) with 0.5 to 10% of O(2), SiO can be readily etched and shaped into patterns using suitable photoresist or metal masks. In 1% 0 plasma at 50 watt power input into a 3 in. diameter and 8 in. long chamber at one torr pressure, the etching rate is approx. 400 angstroms per minute. Under these conditions, the differential etch rate between Shipley AZ 1350H** photoresist and SiO is greater than it is in FREON plasma in the absence of O(2). AZ 1350H photoresist can therefore be used as a mask in etching of SiO(2). When O(2) is excluded, Si0 can be etched with FREON plasma, but the rate of etching is slower. It is assumed that any fluorine based gas such as sulfurhexafluoride (SF(6)) will accomplish a comparable end result.

Unlike sputter etching, this technique is selective. The SiO can be etched in presence of metals which are not attacked by plasma such as: Al, Cu, Au, Ni, and Hi-Fe. SiO can also be etched in the presence of such materials as SiO(2), evaporated glass, single crystal Si, and polysilicon, for which, under comparable conditions, the etch rate is smaller than for SiO. However, SiO is not readily etched in presence of Si(3)N(4), unless a relatively thick Si(3)N(4) layer is used, because the etch rate for Si(3)N(4) is nearly double that for SiO. * Trademark of
E. I. du Pont de Nemours & Co...