Evaluation of 4" InP(Fe) substrates for production of HBTs

Large-scale fabrication of heterojunction bipolar transistors (HBTs) for digital wireless, cellular and fiber optic telecommunication systems is creating a need for high quality, large diameter semi-insulating InP(Fe) substrate crystals. The purpose of this paper is to review the evolution and current state of commercially available 4" InP(Fe) substrates, compared to smaller substrates (Bliss, 1999) and compared to specifications for GaAs(SI) on resistivity, EPD, thickness, flatness and orientation.