Ohmic and Schottky contacts on n-type indium-phosphite

High quality ohmic and Schottky contacts on n-type InP have been developed for high speed effect transistor applications. The requirements for high speed operation mandate that ohmic contacts have very low contact resistance and the Schottky contacts have low leakage currents under applied reverse bias. Fabrication processes include specialized surface preparation, metallization, and annealing cycles. In addition the contacts have been electrically and structurally characterized.;Ohmic contacts have been fabricated on n-type InP with an alloyed AuGe based metallurgy that involved ion milling prior to metallization. Low values for contact resistance and specific resistance were found for contacts fabricated with and without Ni. Minimum values of these two quantities of 0.015 ;Schottky contacts have been fabricated on In-P using a Ag/Al-InP configuration. Appropriate heat treating raises barrier heights by as much as 0.25 eV, resulting in O sbbeff approx 0.65;Changes in contact metallurgy were observed with Auger electron spectroscopy, transmission electron microscopy combined with selected area diffraction, and X-ray diffraction. Auger electron spectroscopy depth profiling studies indicate that aluminum first reacts with the native oxide and then migrates through the silver to the free metal surface upon annealing. Subsequent cooling resulted in the precipitation of Ag...