Interface properties of PNxInP structures by in-situ remote plasma processes

Interfacial properties of Au/PNx/n-InP Schottky junctions and metal-insulator-semiconductor (MIS) diodes formed by a series of in-situ remote plasma processes have been evaluated by measuring electrical characteristics. The in-situ processes consist of removal of native oxide by a H2 plasma, surface modification by a PH3 plasma, deposition of a PNx layer by the use of PH3 and N2 plasma, and subsequent metal evaporation. An effective barrier height of 0.83 eV and a true barrier height of 0.57 eV are observed for the tunnel MIS Schottky junction. An interface state density as low as 1.4 × 1011 eV−1 cm−2 is obtained for the MIS diodes. From the behavior of the true barrier height and the low interface state density, it is suggested that a novel in-situ process is effective in forming an interface of PNxInP structure.