Nitride Chemical Passivation of a GaAs (100) Surface: Effect on the Electrical Characteristics of Au/GaAs Surface-Barrier Structures

The effect of chemical nitridation of GaAs substrates in a hydrazine-sulfide solution on the electrical characteristics of Au/GaAs Schottky structures has been studied. In nitridation of this kind, a solid passivating gallium nitride film with a monolayer thickness is formed on the surface of GaAs, providing almost direct contact between the semiconductor and the metal deposited on its surface. Au/GaAs structures fabricated on nitride substrates have ideality factors close to unity and are characterized by a narrow scatter of potential barrier heights. Prolonged heating of these structures at 350 degrees C does not change these parameters. The data obtained show that the nitride monolayer formed on the GaAs surface upon treatment in hydrazide-sulfide solutions effectively hinders atomic migration across the metal-semiconductor phase boundary.