On the determination of interface state density in n-InP Schottky structures by current-voltage measurements - Comparison with DLTS results

Current voltage (I-V-g) and deep level transient spectroscopy (DLTS) techni ques have been carried out to study Schottky and ultraviolet oxidised Schot tky diodes realised on n-type indium phosphide. For the oxidised structures , the ideality factor n versus voltage exhibits a peak around 0.2 V, from w hich the interface state density can be estimated to have a maximum value o f 4 x 10(12) cm(-2) eV(-1). Comparable results for the same structures have been obtained from DLTS measurements. For the Schottky diodes, no peak app ears in the plot of n versus voltage and no information on interface states can be deduced from I-V-g, measurements. However, DLTS measurements reveal an electrically active defect localised at the InP interface. This study s hows that the I-V-g measurements may be used as a fast technique for interf ace states investigation. (C) 2000 Elsevier Science Ltd. All rights reserve d.