Title :
Theoretical approach to CMOS APS PSF and MTF modeling - evaluation
Author :
Grois, Dan ; Shcherback, Igor ; Danov, Tatiana ; Yadid-Pecht, Orly
Author_Institution :
VLSI Syst. Center, Ben-Gurion Univ., Beer-Sheva, Israel
Abstract :
In this work, a fully theoretical CMOS active pixel sensor (APS) modulation transfer function model is formulated, evaluated, and compared with practical results. The model is based on a two-dimensional diffusion equation solution and covers the symmetrical photocarriers diffusion effect together with the impact of the pixel active area geometrical shape. Thorough scanning results obtained by means of a unique submicron scanning system (the S-cube system) from various APS chips, implemented in a standard CMOS 0.35-μm technology, are compared with our theoretical predictions. The agreement of the presented comparison results indicates that for any potential active area shape, an analytical reliable estimate of image performance is possible.
Keywords :
CMOS image sensors; diffusion; integrated circuit modelling; optical transfer function; photoconducting devices; photoconductivity; transfer functions; 0.35 micron; 2D diffusion equation solution; CMOS active pixel sensor; CMOS image sensors; S cube system; active pixel sensor chips; modulation transfer function model; point spread functions; submicron scanning system; symmetrical photocarriers diffusion effect; CMOS image sensors; CMOS technology; Image analysis; Image quality; Image resolution; Semiconductor device modeling; Sensor arrays; Sensor phenomena and characterization; Shape; Transfer functions; Active pixel sensor (APS); CMOS image sensor; diffusion process; modeling; modulation transfer function (MTF); point spread function (PSF);
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2005.856128
