Materials Technology for InSb Misfet Applications

The narrow and direct bandgap of indium antimonide is frequently used to good advantage in detection of light in the infra-red region; however, to date little use has been made of the high mobilities associated with this material. Although its high intrinsic carrier concentration generally necessitates operation at cooled temperatures, higher speeds and the advantage of integrating other devices on-chip with the infrared detectors encourages the development of an active device technology on this semiconductor. Considering its small bandgap, the problems associated with good p-n junctions may favor the MISFET in this application. Surprisingly, little has been done toward this goal, though structures such as chargecoupled- devices [1], focal array detectors [2], and a few insulated gate FETs [3,4] have been fabricated. In this paper we present the results of our recent work toward the development of a fabrication technology for InSb MISFETs. Specifically, we have conducted a study of etchants, metal contacts, and dielectrics for application to mesa-structure, insulated gate field transistors.