Base and collector leakage currents of AlGaAs/GaAs heterojunction bipolar transistors
Abstract
Base and collector leakage currents are extremely important to AlGaAs/GaAs heterojunction bipolar transistor (HBT) dc characteristics, and a simple model to describe such currents is presented. This study suggests that these currents are originated from the electron and hole leakage through the dielectric-layer (e.g., polyimide, nitride, etc.) interface at the emitter-base and base-collector peripheries, as well as through the n+-subcollector/semi-insulating substrate interface. Five HBTs having similar intrinsic make-ups (i.e., doping concentration and layer thickness) but different extrinsic make-ups (i.e., finger pattern, perimeter, dielectric layer, etc.) are investigated, and with the aid of the model, the possible mechanisms contributing to their leakage behavior identified.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- September 1994
- DOI:
- 10.1063/1.357502
- Bibcode:
- 1994JAP....76.3187L
- Keywords:
-
- Aluminum Gallium Arsenides;
- Bipolar Transistors;
- Current Distribution;
- Heterojunction Devices;
- Leakage;
- Mathematical Models;
- Chemical Reactions;
- Emitters;
- Solid-Solid Interfaces;
- Substrates;
- Solid-State Physics