ABSTRACT
This chapter presents an overview of various types of smart pixels, and materials and provides dedicated pixel arrangement and optics for smart complementary metal-oxide-semiconductor (CMOS) image sensors. It examines structures and materials other than standard silicon CMOS technologies are introduced for certain CMOS image sensors. The principle of the self-reset type CMOS image sensor is almost the same as that of pulse frequency modulation. Silicon-on-insulator (SOI) based CMOS image sensors are developed for the detection of high energy particles. The sensor consists of a conventional silicon (Si)-CMOS image sensor and a Ge photodiode (PD) array formed underneath the CMOS image sensor. Photo-generated carriers in the Ge (PD) region are injected into the (Si) substrate and reach the photo-conversion region at a pixel in the CMOS image sensor by diffusion. The three-dimensional image sensor in the figure is fabricated after the fabrication of the backside-illuminated CMOS image sensor wafer, which is bonded with another SOI based wafer where circuits are employed.
