The Use of Amorphous SiO and SiO[sub 2] to Passivate AuGe-Based Contact for GaAs Integrated Circuits

We have successfully demonstrated the use of electron-beam-deposited SiO and SiO2 to passivate AuGe-based ohmic contacts to prevent galvanic effect etching during GaAs sample cleaning with deionized water and HCl/H2O. There were no apparent changes of the specific contact resistivity and sheet resistance after cleaning with the oxide passivation. A transmission line method was employed to monitor the erosion of the epitaxial GaAs layer. The wet and dry etching characteristics of SiO2 are similar to those of plasma-enhanced chemical vapor deposited SiO2; however, the etch rates of SiO are reduced in both cases. (C) 1999 The Electrochemical Society. S1099-0062(99)02-060-1. All rights reserved.