Browse Prior Art Database

Etching Technique

IP.com Disclosure Number: IPCOM000087851D
Original Publication Date: 1977-Mar-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Kane, SM: AUTHOR [+2]

Abstract

Material which is deposited by sputtering generally strongly adheres to the substrate surface on which it is deposited due to interfacial mixing. For example, when SiO(2) is sputtered onto an Au film, there is a thin layer (on the order of 0.1 micron), which is a mixture of Si, O, and Au, at the interface of the SiO(2) and Au. Although this is helpful for adhesion, it is difficult to etch, and, therefore, the definition of patterns in the SiO(2) layer is difficult to achieve using conventional chemical etching.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Etching Technique

Material which is deposited by sputtering generally strongly adheres to the substrate surface on which it is deposited due to interfacial mixing. For example, when SiO(2) is sputtered onto an Au film, there is a thin layer (on the order of 0.1 micron), which is a mixture of Si, O, and Au, at the interface of the SiO(2) and Au. Although this is helpful for adhesion, it is difficult to etch, and, therefore, the definition of patterns in the SiO(2) layer is difficult to achieve using conventional chemical etching.

The drawing shows the type of etching which would occur if buffered HF is used for this purpose. The etching often stops, incomplete, at the interface boundary layer. Even if longer etching times are used, the interface layer will not be etched but rather lateral etching will occur, and often the resist itself will begin to peel off.

In order to overcome these disadvantages, a combination of chemical etching and ion milling etching is used. Although ion milling alone is not practical due to the slow milling rate of SiO(2), ion milling can be combined with chemical etchants to provide successful etching. A minimum exposure time for chemical etchants, followed by ion milling will produce holes in the SiO(2) having a minimum of undercutting and with no contact problems due to interfacial residue. Further, there will be no loss of a pattern due to peeling resist.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]