RF control of epitaxial lift-off PHEMT's under backside illumination

This paper presents the optical response of the DC and the RF (C-Band) performance of a 1 /spl mu/m gate length epitaxial lift-off PHEMT device under backside illumination. The device when biased near pinch off exhibited an increase of S/sub 21/, G/sub max/, and g/sub m/ of 1.2 dB, 2 dB, and 56%, respectively. The measured responsivity was as high as 13.4 A/W with a quantum efficiency of 2300 percent. These results far exceeded previously reported performances for devices under frontside illumination. >