Measurement of Minority Carrier Diffusion Length and Band Gap Narrowing in Heavily Doped n-Type Base Regions of Silicon p-n-p Lateral Transistors

Abstract

Lateral p-n-p transistors with varying base widths have been fabricated in laboratory by diffusion of boron in heavily doped n-type silicon samples in the doping range from 5 × 1018 to 2.5 × 1019 cm−3. These devices have been employed as vehicles to determine the effective intrinsic carrier concentration and the minority carrier diffusion length. From these parameters, the effective band gap narrowing and minority carrier lifetime have been calculated as functions of the dopant concentration in n-type silicon. The values obtained from these studies are in reasonably good agreement with the results of other investigators.