EFFECTS OF BROMINE-METHANOL AND HYDROGEN-CHLORIDE PRETREATMENTS ON PTAL/N-INP DIODES/

This paper reports the passivation effects of bromine-methanol (Br/M) and hydrogen chloride (HCl) treatments on the n-InP surface to form Pt /Al/n-InP diodes. It was found that Br/M and HCl passivated the n-InP surface. The Br/M-dipped and the HCl-dipped Pt/Al/n-InP diodes exhibit ed a barrier height of 0.83 and 0.86 eV, respectively, and a low rever se leakage current of 7.07 x 10(-7) and 1.10 x 10(-7) A/cm(2) at -3 V, respectively. The secondary ion mass spectroscopy and electron spectr oscopy for chemical analysis showed that the Br/M or HCl treatment mad e formation of bromides and chlorides on the n-InP surface, respective ly. They also revealed the existence of Al2O3, which is believed to be formed with the native In2O3 during the Al evaporation. This, which m ade the diodes be of the metal-insulator-semiconductor structure, in c onjunction with the passivation effect of bromides and chlorides, impr oved the diode characteristics and produced the high barrier heights.