Measurement of the electron ionization coefficient temperature dependence in InGaAs-based heterojunction bipolar transistors

In this paper the temperature dependence of the electron ionization coefficient ¿n at low electric fields in In0.53Ga0.47As is determined by means of multiplication factor M-1 measurements in AlInAs/In0.53Ga0.47As/InP Heterojunction Bipolar Transistors. As opposed to the behavior found in most other semiconductors, our measurements show that alpha increases with increasing temperature. This can be a critical effect in power devices, where a positive feedback between power dissipation and impact ionization multiplication may set up.