Journal of Vacuum Science & Technology B, Vol.18, No.1, 150-155, 2000
Substrate transfer process for InP-based heterostructure barrier varactor devices
We report on transferred-substrate InP-based heterostructure barrier varactor (HBV) devices. Individual HBV devices having active device diameters ranging from 10 to 40 mu m have been fabricated on a SiO2 glass host substrate following a novel epitaxial layer transfer technique: This process utilizes the negative photoresist SU-8 as a photopatternable intermediate bonding layer and could be extended to other InP-based devices. The transferred HBV device characteristics have been measured and compared to devices which have been fabricated on InP. The transferred devices exhibited highly symmetrical electrical characteristics due to the preservation of the high quality molecular beam epitaxy layers during the transfer process. A leakage, current of 4.5 A/cm(2) at 10 V together with an associated conductance value of 40 nS/mu m(2) were observed. The rf measurements revealed a zero bias capacitance of 1 fF/mu m(2) and a capacitance ratio of 5:1,
Keywords:LIFT-OFF