Experimental and Monte Carlo analysis of impact-ionization in AlGaAs/GaAs HBT's

We present a detailed experimental and theoretical investigation of hot electron effects occurring in AlGaAs/GaAs Heterojunction Bipolar Transistors (HBT's) operating at low current densities. Electrons heated by the strong electric field at the base-collector junction give rise to impact ionization and light emission. A new general purpose weighted Monte Carlo procedure has been developed to study such effects. The importance of dead-space effects on the multiplication factor of the device is demonstrated. Good agreement is found between theory and experiment.