The Effect of Thermal Annealing and Measurement Temperature on Interface State Density Distribution and Time Constant in Ni/N-Gap Rectifying Contacts

Abstract

The capacitance-frequency (C-f) and conductance-frequency (G-f) characteristics of the as-deposited and 400A degrees C annealed Ni/n-GaP/Al diode were measured in a temperature range of 100-320 K with steps of 20 K. The values of interface state density N (ss) and their time constant were obtained from the temperature-dependent C-f and G-f characteristics in the measurement frequency range of 5.0 kHz to 5 MHz. The effect of annealing and measurement temperature on N (ss) and time constant of a Ni/n-GaP Schottky diode were analyzed from the forward bias voltage to the reverse bias voltage - 0.60 with steps of 0.30 V. The N (ss) value ranges from 8.8 x 10(11) cm(-2)eV(-1) at 0.60 V to 5.71 x 10(11) cm(-2)eV(-1) at - 0.60 V for the as-deposited diode, and 1.3 x 10(12) cm(-2)eV(-1) at 0.60 V to 5.5 x 10(11) cm(-2)eV(-1) at - 0.60 V for the 400A degrees C annealed diode at a measurement temperature of 300 K. The interface state density value increases with high measurement temperature for the as-deposited and annealed diode.