Development of Refractory NiGe-based Ohmic Contacts to n- type GaAs

摘要

Thermally stable, low resistance NiGe-based Ohmic contacts to n-type GaAs were developed by adding a small amount of a third element (Au, Ag, Al, Pd, or In) to the refractory NiGe compound contacts. These NiGe-based contacts had smooth surface and shallow diffusion depth, which are required for the future very large scale integration (VLSI) GaAs devices. The electrical properties were correlated with the microstructure by analyzing the interfacial structure using high-resolution electron microscopy, which enabled us to propose models for the current transport mechanism of the NiGe-based contacts. These models explained nicely the effect of the third elements on the electrical properties of the NiGe Ohmic contacts.