Si permeable-base transistor realization using a MOS-compatible technology

Silicon permeable-base transistors (PBTs) fabricated using a process entirely compatible with MOS technologies are discussed. The critical lithography defining the metal-base grating is an optical lithography, which allows easy variable periodicity of the base grating, and therefore permits the realization of PBT with either normally-on or normally-off transistor characteristics. Because of the high current density achievable in these devices and the high degree of compatibility with MOS technologies, PBT is a possible alternative for BICMOS applications.>