Penetration depth of Pd/Ge/Ti/Au ohmicPenetrationcontact to high-low-doped n-GaAs has been investigated using cross-sectional transmission electron microscopy, and the results are used to interpret the electrical properties. The ohmic metals do not penetrate into the GaAs substrate at 300°C, but penetrate deeper than 1000 Å into GaAs at 380°C. This is due to fast indiffusion of Au toward the GaAs substrate through the grain boundary of the PdGe compound, followed by formation of AuGa through reaction with GaAs. The deep penetration into GaAs at 380°C results in the lowest contact resistance of 0.43 Ωmmdue to direct contact of ohmic metals with the buried high-doped GaAs layer.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)