MOCVD-grown 175 GHz InP-GaAs/sub x/Sb/sub 1-x/-InP DHBTs with high current gains using strained and heavily C-doped base layers

Abstract

Summary form only given. In this paper, we report high current gain InP-GaAsSb-InP DHBTs implemented with a 200 /spl Aring/ thick strained GaAs/sub 0.6/Sb/sub 0.4/ highly-doped base layer (C: 8/spl times/10/sup 19/ cm/sup -3/). The devices exhibit peak cut-off frequencies f/sub T/= 175 GHz and f/sub max/=106 GHz with a BV/sub CEO/=6 V and a DC current gain /spl beta/=200-300 which can be traded off for higher f/sub max/ values. The devices behave extremely well even at low supply voltages: f/sub T/ remains above 150 GHz (125 GHz) for V/sub CE+/=0.75 V (0.55 V). This work is the first demonstration of a sub-picosecond transit time for an HBT with a base material other than GaInAs or GaAs, and we attribute the tenfold increase in /spl beta/ with respect to our previous work (Bolognesi et al, 1999) on the use of a strained As-rich base layer.