CMOS Global Shutter Charge Storage Pixels with Improved Performance

Abstract

We describe different charge-storage-based global shutter (GS) pixel architectures with improved performance resulting from low dark current and effective pixel pitch reduction from 6 to 2.8 'Êm pixel size. Smaller pixels showed better image quality versus larger pixels at low exposures and higher temperatures. In addition to earlier disclosed work, we proposed and have developed novel high GS efficiency (GSE) pixel modules such as the improved tungsten buried light shield and the pixel light guide structures. The GS pixel simulation and measurements showed significant improvement in sensitivity, dark current, and GSE. These pixels and modules have been implemented in a variety of ON Semiconductor sensors. More than 1.2× area-scaled sensitivity improvements, more than 20× improvement in average storage dark current, and from 7× to more than 38× GSE improvement at different light wavelengths were demonstrated.