Browse Prior Art Database

Use of a Bias Sputtered Film to Stress Bulk Material or Another Film

IP.com Disclosure Number: IPCOM000078584D
Original Publication Date: 1973-Feb-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Blachman, AG: AUTHOR

Abstract

A procedure is taught for using a bias-sputtered film deposited onto the back of a substrate, for the purpose of controllably stressing either the substrate or a film (or films) previously deposited on the front of the substrate.

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 59% of the total text.

Page 1 of 2

Use of a Bias Sputtered Film to Stress Bulk Material or Another Film

A procedure is taught for using a bias-sputtered film deposited onto the back of a substrate, for the purpose of controllably stressing either the substrate or a film (or films) previously deposited on the front of the substrate.

In Figs. 1A and 1B, a film 2 deposited upon the front surface of a substrate 4 could apply either external tensile stress, as in Fig. 1A, or external compressive stress, as in Fig. 1B. If such stresses are sought, then the stressed substrate in its curved state is used. However, in many applications it is desired to retain the characteristics of deposited film 2, but reduce the substrate curvature. In the case of Fig. 1A, it is possible, while maintaining substrate 4 at a relatively low temperature of 70 degree C, to sputter a film 6 of molybdenum onto the back surface of the substrate so as to return the substrate to its uncurved condition.

It has been found that by choosing a DC sputtering bias of -75 volts for molybdenum, a film 6 of Mo is deposited that is stressed tensily so as to compensate for the external tensile stress on the front of the substrate. If a DC sputtering bias of the substrate is -150 volts, then the back side film of Mo is stressed compressively, and will offset the curving effect of the externally applied compressive stress of the front film. Where the substrate is a 1000-6000 Angstrom thick wafer of oxidized silicon, the substrate can be control...