Surface Passivation Using P 2 S 5 /(NH 4 ) 2 S x and Hydrogen Fluoride Solutions on Ag/n-InAs and Ag/n-InSb Schottky Diodes

A method for surface passivation using both phosphorus sulphide/ammonia sulphide [P 2 S 5 /(NH 4 ) 2 S x ] and hydrogen fluoride (HF) solutions has shown great effectiveness for the reduction of InAs and InSb substrate surface oxides. In comparison with samples treated by P 2 S 5 /(NH 4 ) 2 S x or HF solutions alone, the surface layer produced by the new passivation treatment has a high stability against oxidation even after an 18 h baking treatment at a temperature of 300°C in N 2 ambient. In addition, the barrier heights of Ag/n-InAs and Ag/n-InSb Schottky diodes can still reach as high as 0.37 and 0.19 eV, respectively, even though the Ag/n-InAs and Ag/n-InSb diodes were baked for 18 h at 300°C.