A 60 GHz high power composite channel GaInAs/InP HEMT on InPsubstrate with L_G=0.15 μm

摘要

We have improved power performance by studying three differentGaInAs/InP composite channel structures. Also, different gate to drainextension devices have been processed. By using composite channeldevices, we benefit from the better ionization threshold energy of InPcompared to GaInAs (1.69 eV against 0.92 eV). The difference ofconduction band offset between the two materials(ΔE_C=0.2 eV) makes possible electron transfer fromGaInAs to InP layers with the same electronic properties. New processtechnologies have been applied to compare these structures. The gatecurrent resulting from the impact ionization phenomena is reduced to 30μA at V_DS=4.5 V for a large extension device, whichconstitute the best result among the three structures. Also, we improvepower performances at 60 GHz by reducing the GaInAs channel width andsubstituting delta doping by bulk doping. The best device performance is422 mW/mm at V_DS=3 V and V_GS=0.7 V