Fully-Depleted Silicon-on-Insulator (FDSOI) Based Complementary Phototransistors for In-Sensor Vector-Matrix Multiplication

Two type CMOS-compatible complementary phototransistors (CPTs) with NMOS or PMOS transistor are proposed in this work for in-sensor vector-matrix multiplication (VMM). The CPT is fabricated by the 22nm FDSOI process technology and composed of a MOSFET with a p-doped well under the buried oxide (BOX). The well serves for photoelectron generation and affects the on-state current of the MOSFET by the photoelectrons. The bidirectional and tunable photoresponsivity characteristics as well as the optical-electrical signed multiplication operation (average error < 2.5%) are experimentally demonstrated in the pair of CPTs. The in-sensor VMM is verified by typical artificial neural networks using the CPT array as the image-input layer. Simulated results show slight inference accuracy losses (< 1%) in LeNet3 for MNIST and VGG11/VGG16 for CIFAR-10 recognition.