RF CONTROL OF EPITAXIAL LIFT-OFF PHEMTS UNDER BACKSIDE ILLUMINATION

This paper presents the optical response of the DC and the RF (C-Band) performance of a 1 mum gate length epitaxial lift-off PHEMT device under backside illumination. The device when biased near pinch off exhibited an increase of S21, G(max), and g(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.