Skip to Main Content
Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1063/1.336143
Dielectrically isolated silicon was produced by anodically bonding together a pair of silicon wafers whose surfaces were covered with an electrically nonconductive micron layer of thermally grown oxide. Although anodic bonding normally requires a conductive oxide, anodic bonding works with nonconductive silicon oxide if the total layer of silicon oxide is less than ten microns thick. The time needed for the anodic bonding process decreases monotonically with temperature because the increase in the deformability of silicon oxide overcomes the decrease in the maximum permissible anodic bonding voltage with temperature. However, factors such as silicon degradation and electrode reactions at very high temperatures indicate that a compromise temperature range of 850–950 °C is best for the anodic bonding of silicon oxide. Bonding voltages of 30–50 V for times of about an hour produced the best bonding yields at these temperatures. Anodically bonded silicon wafers were examined with infrared and ultrasonic transmission microscopy for bond quality. Small scattered nonbonded zones comprising on the average 5% of the total wafer area were found in all wafers. These nonbonded zones were the result of dust particles, entrapped gas, and dimensional mismatches between multiple bonding fronts.