Title of Presentation: Fabrication and Modeling of a Nano-multiplication-region Avalanche Photodiode

Primary (Corresponding) Author: Xinyu Zheng

Organization of Primary Author: NASA Jet Propulsion Laboratory

Co-Authors: K.L. Wang

Abstract: Fabrication and modeling as well as the first test results of a prototype Nano-multiplication-region Avalanche Photodiode (NAPD) are presented. The NAPD is designed for a crosstalk-free imaging array that is capable of performing photon detectable imaging in the wave range of 250-1000 nm with high quantum efficiency, high dynamic range and low dark count rate. The prototype NAPD composes a nano-pillar, which contains the multiplication region and the reach-through structures of the avalanche photodiode, a thick SOI absorption region with a back doping layer and a floating cathode located on the shoulder of the device for the purpose of expanding the depletion region to the farthest edge of the detector. Special processing technologies including nano-pillar fabrication, nano-multiplication-region and nano-reach-through structure formation and nano-cathode interconnection have been developed for fabrication of the prototype. Quasi three dimensional NAPD modeling consisting of combined process simulation and device simulation shows that, besides the advantages of low dark count rate and low voltage, a unique avalanche mode, i.e. the self-quenching avalanche featuring a stable gain over a certain bias range, can be realized with proper structural parameters. The nano-pillar geometry and reach-through parameter dependences of the stable gain are presented and discussed.