Transport mechanisms and interface properties of W/p-InP Schottky diode at room temperature

Abstract

We have investigated the electrical properties and current transport mechanisms of W/p-InP Schottky diode using current–voltage (I–V), capacitance–voltage–frequency (C–V–f) and conductance–frequency (G–f) techniques at room temperature. The W/p-InP Schottky diode exhibits a good rectifying behavior. Measurements show that the Schottky barrier height (SBH) and ideality factor of the W/p-InP Schottky diode are 0.84 eV (I–V)/0.98 eV (C–V) and 1.24, respectively. Also, the SBH and series resistance R s of the diode are extracted by Cheung’s functions and the values are in good agreement with each other. Ohmic and space charge-limited conduction mechanisms are found to govern the current flow in the W/p-InP Schottky diode at low and high forward bias conditions, respectively. Experimental results reveal that the Poole–Frenkel mechanism is found to be dominant in the reverse bias region of W/p-InP Schottky diode. Further, the interface state density N ss and their relaxation times τ of the W/p-InP Schottky diode are estimated from the forward bias C–f and G–f characteristics and the values are in the range from 1.95 × 1013 eV−1 cm−2 and 3.38 × 10−5 s at (0.81-E V ) eV to 1.78 × 1013 eV−1 cm−2 and 2.78 × 10−6 s at (0.30-E V ) eV, respectively. Both the N ss and τ show an exponential rise with bias from the top of the valance band toward the mid gap.