Share Email Print

Proceedings Paper

Modeling of CMOS image sensors for time-of-flight applications
Author(s): Adrian Driewer; Bedrich J. Hosticka; Andreas Spickermann; Holger Vogt
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

This contribution describes the modeling of CMOS image sensors employed in time-of-flight (ToF) sensor systems for 3D ranging applications. Our model relies on the theoretical description of photo-generation, charge transfer including diffusion, fringing field, and self-induced drift (SID). This method makes it possible to calculate the time-dependent charge carrier generation, transfer, and distribution. The employed approach allows elimination not only of irradiance-dependent charge transfer, but also of undesired reflectance effects, and the influence of ambient light through an in-pixel background measurement. Since the sensor is operated with very short integration times it is crucial to accomplish a fast transfer of the generated charge from the photodetector to the sense node, and speedy conversion into an electrical signal at its output. In our case, we employed a lateral drift field photodetector (LDPD), which is basically a pinned photodiode with a built-in drift field formed by a doping gradient. A novel pixel structure is presented which is optimized for a fast charge transfer by the appliance of the shown model. Numerical calculations predict a two times faster charge collection.

Paper Details

Date Published: 5 May 2015
PDF: 9 pages
Proc. SPIE 9506, Optical Sensors 2015, 950603 (5 May 2015); doi: 10.1117/12.2178390
Show Author Affiliations
Adrian Driewer, Fraunhofer-Institut für Mikroelektronische Schaltungen und Systeme (Germany)
Bedrich J. Hosticka, Fraunhofer-Institut für Mikroelektronische Schaltungen und Systeme (Germany)
Andreas Spickermann, Fraunhofer-Institut für Mikroelektronische Schaltungen und Systeme (Germany)
Holger Vogt, Fraunhofer-Institut für Mikroelektronische Schaltungen und Systeme (Germany)

Published in SPIE Proceedings Vol. 9506:
Optical Sensors 2015
Francesco Baldini; Jiri Homola; Robert A. Lieberman, Editor(s)

© SPIE. Terms of Use
Back to Top