Vertical gallium nitride containing field effect transistor with silicon nitride passivation and gate dielectric regions

Abstract

A Low Pressure Chemical Vapor Deposition (LPCVD) technique is provided to produce improved dielectric/semiconductor interfaces for GaN-based electronic devices. Using the LPCVD technique, superior interfaces are achieved through the use of elevated deposition temperatures (>700° C.), the use of ammonia to stabilize and clean the GaN surface, and chlorine-containing precursors where reactions with chlorine remove unwanted impurities from the dielectric film and its interface with GaN. The LPCVD silicon nitride films have less hydrogen contamination, higher density, lower buffered-HF etch rates, and lower pin hole density than films produced by other deposition techniques making the LPCVD coatings suitable for device passivation. A metal insulator semiconductor (MIS) structures fabricated with LPCVD SiN on GaN exhibit near ideal capacitance-voltage behavior with both charge accumulation, depletion, and inversion regimes.