One dimensional modeling of trim transistors

A one dimensional approximation of the TRIM transistor consists of an electron-hole plasma in series with a high field near the intrinsic region. Our analysis of this type of structure differs from a previous one in that it allows a variable plasma width, V/cm V/cm where Wbis plasma width, Jbis base current density, VTis collector voltage and ε is electric field in the high field region. This expression is valid when where WTis the width of the near intrinsic region. Given a plasma density greater than the background doping density, the current gain ratio for pnp-type structures is identical in form to that of npn-type structures, i.e., , where is a carrier diffusion length for emitter injected carriers. The analytical closed form solution gives physical insight into TRIM design and compares favorably to the more accurate computer analysis.