A Novel Surface Pivation Structure for III-V Compound Semiconductors Utilizing a Silicon Interface Control Layer and its Application

Abstract

ABSTRACTThe present status of surface passivation research for III-V compound semiconductors utilizing a novel unique structure including a silicon interface control layer (Si ICL) is presented and discussed. The basic principle of passivation is to insert an ultrathin MBE-grown Si layer between the III-V compound semiconductor and a Si-based thick insulator so as to terminate the surface bonds of the III-V material with Si atoms and then to transfer Si-bonds smoothly to those of the Si based insulator. Based on the calculation of quantized levels in strained Si ICL, the passivation structure was optimized. Such a structure was realized by partial nitridation of Si ICL surface. In-situ surface characterization techniques including newly developed UHV contactless C-V technique, were used for optimization of each passivation step. Surface reconstruction of initial semiconductor surface was found to have a great influence on passivation. In the case of GaAs, the c(4×4) surface is preferable to the (2×4) surface. The novel process has realized the oxide-free surface passivation of InP with a Nssmin value of 2 × 1010 cm−2 eV−1. Furthermore, the novel passivation technique has been successfully applied to the fabrication of MISFETs and IGHEMTs, and the passivation of quantum structures.