Electrical and 850 nm Optical Characterization of Back-Gate Controlled 22 nm FDSOI PIN-Diodes Without Front-Gate

Abstract

We present electrical and optical $(\lambda =\rm {850~nm })$ measurement results of back-gate controlled SOI PIN-diodes without a front-gate, with an intrinsic Si film thickness of only ${\sim }\rm 6nm $ . These ultrathin-body PIN-diodes were fabricated as exploratory devices in a commercially available Fully-Depleted Silicon-On-Insulator (FDSOI) technology, without requiring additional process steps. We show that electrostatic back-gate tuning significantly affects the electrical characteristics and optical responsivity $({{R_{\mathrm { o}}}{}})$ . This leads to a novel method to extract the optimal back-gate bias for maximum ${R_{\mathrm { o}}}{}$ from electrical measurements. The maximal measured ${R_{\mathrm { o}}}{}$ at 0V bias across the diode and with optimal back-gate bias equals $62{\mu }$ A /W, with a -3dB bandwidth of 5.9GHz, and a -6dB bandwidth of 15GHz. These PIN-diodes potentially open the way to new (THz) circuits, sensors, novel/complementary process control monitoring structures, and optical applications. They also enable interaction between the hybrid (bulk) and SOI devices, which is a unique feature of FDSOI technologies.