J. Phys. III France
Volume 5, Numéro 5, May 1995
Page(s) 509 - 517
DOI: 10.1051/jp3:1995134
J. Phys. III France 5 (1995) 509-517

LF Excess Noise of AlGaAs/GaAs and AlGaAs/InGaAs/GaAs HEMTs

N. Saysset1, C. Maneux1, N. Labat1, A. Touboul1, Y. Danto1 and J.M. Dumas2

1  IXL, URA 846-CNRS, University Bordeaux I, 351 Cours de la Libération, 33405 Talence, France
2  ENSIL, 83 rue d'Isle, 87000 Limoges, France

(Received 8 July 1994, revised 14 December 1994, accepted 26 January 1995)

The quality of AlGaAs/GaAs/buffer layer on GaAs HEMTs and of AlGaAs/InGaAs/GaAs HEMTs is studied on the basis of technological parameter influence: Al molefraction in the n-AlGaAs layer, type of the buffer layer (p- or n- doped GaAs or AlGaAs), in molefraction in pseudomorphic structures. From the LF drain noise behaviour versus gate and drain biases and temperature (90K to 300K), pseudomorphic devices are found to present lower drain current noise and less G-R contributions when compared to conventional HEMTs. This difference might result from a lower deep level concentration.

© Les Editions de Physique 1995