Silicon-on-Insulator Photodiode on Micro-Hotplate Platform with Improved Responsivity and High-Temperature Application

Li, Guoli [UCL] André, Nicolas [UCL] Poncelet, Olivier [UCL] Gérard, Pierre [UCL] Ali, Syed Zeeshan [Cambridge CMOS Sensors Ltd., UK] Udrea, Florin [Cambridge CMOS Sensors Ltd., UK] Francis, Laurent [UCL] Zeng, Yun [School of Physics and Electronics, Hunan University, China] Flandre, Denis [UCL] et al.[show all]

This paper reports on the performances of a silicon-on-insulator (SOI) photodiode suspended on a dielectric membrane. The micro-hotplate platform consists of a micro-heater and a thin-film lateral P+/P-/N+ (PIN) photodiode. Without optimizing the multilayer stack on top of the PIN diode, experimental responsivities of the suspended photodiodes at room temperature (RT) are 0.02-0.06 A/W within the visible and near IR light range, under a reverse bias of -2.0 V. Up to 2.5x responsivity improvement has been achieved with regards to the diodes on the substrate thanks to reflection from the gold finish layer of the device package acting as a bottom mirror. Optimizing the layer stack above the diode, the responsivity of the on-membrane device can be theoretically improved up to 0.09-0.11 A/W within 450-520 nm wavelength range. Measured from RT up to 200 °C, the photodiodes on membrane continuously show improved optical response under high-power LED illumination. Assisted by the micro-heater as heat source, the suspended photodiode can work stably up to 200 °C with in-situ temperature sensing and control, which makes it highly suitable and attractive for high-temperature application. Full two-dimensional (2-D) ATLAS device simulations have been comprehensively performed to investigate the optical and electrical characteristics. Very good agreement has been achieved between the numerical simulations and the experimental data.