76‐2: <i>Invited Paper:</i> Optical Fingerprint Sensor Based on a‐Si:H TFT Technology

Abstract

In this report, hydrogenated amorphous Si (a‐Si:H) TFT technology based optical fingerprint sensors are demonstrated. Our a‐Si:H fingerprint sensor technology has the advantages over CMOS fingerprint sensor technology with regard to internal quantum efficiency in accordance with our simulations, expandability to large area, insensitivity to IR light and cost efficiency. We have successfully developed three types of fingerprint sensor modules which we name thin optical touch (TOT), hidden optical touch (HOT) and hidden under display (HUD) sensors. Each sensor module is designed accordingly for a particular application. Our sensor size ranges from small size (4.0 mm x 8.0 mm) for smartphone user identification to 4 finger size (3.2” x 3.0”) for public security check.