One-Step Silicon Nitride Passivation by ECR-CVD for Heterostructure Transistors and MIS Devices

ABSTRACTSilicon nitride (SiNx) films with extremely low interface charge densities have been developed by electron cyclotron resonance-chemical vapor deposition (ECR-CVD) deposition on GaAs substrates. The procedure is a one-step process and does not involve H2 and/or N2 pre-treatment of the sample surface. Characterization by Fourier transform infrared (FTIR) and ellipsometry analysis indicate good properties of the film revealing N-H and Si-N bonds. Results of capacitance-voltage (C–V) measurements show surface charge densities on the order of 5 × 1010 cm−2, which we believe is the lowest surface charge density achieved so far over GaAs.