Effects of Phosphine-Plasma Treatment on Characteristics of Au/n-InP Schottky Junctions

The effects of phosphine (PH 3 )-plasma treatment on the characteristics of Au/n-InP Schottky junctions are investigated and compared with those of hydrogen (H 2 )-plasma treatment. An enhancement of the barrier height of as high as 0.7 eV or more is found for Schottky junctions fabricated by the process consisting of plasma treatment, oxidation and Au evaporation. In the case of PH 3 -plasma treatment, no degradation of the ideality factor occurs and change in the barrier height is suppressed even after annealing at temperatures as high as 350°C. Formation of Schottky junctions is attempted by using an in situ process of H 2 -plasma treatment and metallization in order to reveal the effect of oxidation on variation in the Schottky barrier height. It is demonstrated that the enhancement of barrier height is due to the combined effects of H passivation of the surface defects and surface oxidation.