Maskless all-UHV process for III-V compound semiconductors

Abstract A concept of all-UHV (ultra-high vacuum) resistless process for III-V compound semiconductors is described. This new technology is based on focused ion beam (FIB) doping and molecular beam epitaxy (MBE) in a clean-UHV environment. The submicron-diameter focused ion beams (FIBs) of multiple ion species, which are emitted from a field emission liquid metal ion source (LMIS) are powerful tools for maskless etching, doping, and deposition. Recent developments in FIB processes for III-V compound semiconductors are described, including multicomponent liquid metal ion sources, a focused ion beam implanter, and the physical characteristics of implanted GaAs. Second, preliminary tests of a new compound crystal growth system consisting of MBE layer growth linked with the maskless FIB doping are described. This new technique has been actually used to fabricate planar structures suitable for electrical and optical device integration. Third, innovative UHV processes using electron and photon beams are described, which will play complementary roles to the FIB-MBE processes, in order to make maskless all-UHV processing practical. Based on the FIB-MBE combination technology and other UHV process technique, a prospective all-UHV process is proposed and its potential feasibility is demonstrated by estimating the tumaround-time needed to produce sophisticated integrated circuits such as optoelectronic integrated circuits (OEICs). Key Words: III-V compound semiconductorsplannar structureUHVfocused ion beamsmaskless doping and etching