A triple channel HEMT on InP (Camel HEMT) for large-signal high-speed applications

A triple channel HEMT structure grown on InP has been developed (the "Camel " HEMT), Starting from a dual channel (InGaAs/LnP) HEMT that utilizes both the high electron mobility of InGaAs and the low impact ionization coeffici ent of InP, a third InGaAs channel as well as a quaternary carrier supply l ayer have been introduced to improve the electron transfer and thus the tra nsistor performance. The design of the new transistor structure and its fab rication technology are described. Static and dynamic performances for an 0 .8 m gate length Camel HEMT are presented and compared to standard double c hannel HEMT transistors that are fabricated with the same geometry and proc ess conditions. The results show that this new structure offers a very good tradeoff between high breakdown voltage and current gain cutoff frequency.