Title :
Impact ionization in InP-based HEMTs
Author :
Webster, Richard T. ; Anwar, A.F.M. ; Wu, Shangli
Author_Institution :
Rome Lab., Hanscom AFB, MA, USA
Abstract :
A physical model of impact ionization in InP HEMTs is developed and incorporated in an equivalent circuit model for comparison with experimental observations showing excellent agreement. Impact ionization is modeled by a voltage dependent current source in an RC network at the drain end. The RC branch behaves like a low pass filter that imparts a frequency dependence to the impact ionization current source and enables one to model the inductive nature of S22 at low frequencies. Theoretical calculations show a compression of transconductance due to impact ionization with increasing gate bias that is supported by experimental data. Finally, an experimental method is suggested to extract impact ionization induced transconductance using Y21
Keywords :
III-V semiconductors; S-parameters; equivalent circuits; high electron mobility transistors; impact ionisation; indium compounds; microwave field effect transistors; millimetre wave field effect transistors; semiconductor device models; 0.4 to 40 GHz; InP; InP-based HEMTs; RC network; equivalent circuit model; frequency dependence; gate bias; impact ionization; physical model; transconductance compression; voltage dependent current source; Indium compounds;
Conference_Titel :
High Speed Semiconductor Devices and Circuits, 1997. Proceedings., 1997 IEEE/Cornell Conference on Advanced Concepts in
Conference_Location :
Ithaca, NY
Print_ISBN :
0-7803-3970-3
DOI :
10.1109/CORNEL.1997.649356
