%0 Journal Article
%T Toward One Giga Frames per Second ¡ª Evolution of in Situ Storage Image Sensors
%A Takeharu G. Etoh
%A Dao V. T. Son
%A Tetsuo Yamada
%A Edoardo Charbon
%J Sensors
%D 2013
%I MDPI AG
%R 10.3390/s130404640
%X The ISIS is an ultra-fast image sensor with in-pixel storage. The evolution of the ISIS in the past and in the near future is reviewed and forecasted. To cover the storage area with a light shield, the conventional frontside illuminated ISIS has a limited fill factor. To achieve higher sensitivity, a BSI ISIS was developed. To avoid direct intrusion of light and migration of signal electrons to the storage area on the frontside, a cross-sectional sensor structure with thick pnpn layers was developed, and named ¡°Tetratified structure¡±. By folding and looping in-pixel storage CCDs, an image signal accumulation sensor, ISAS, is proposed. The ISAS has a new function, the in-pixel signal accumulation, in addition to the ultra-high-speed imaging. To achieve much higher frame rate, a multi-collection-gate (MCG) BSI image sensor architecture is proposed. The photoreceptive area forms a honeycomb-like shape. Performance of a hexagonal CCD-type MCG BSI sensor is examined by simulations. The highest frame rate is theoretically more than 1Gfps. For the near future, a stacked hybrid CCD/CMOS MCG image sensor seems most promising. The associated problems are discussed. A fine TSV process is the key technology to realize the structure.
%K imaging device
%K high-speed
%K image sensor
%K BSI
%K ISIS
%K ISAS
%U http://www.mdpi.com/1424-8220/13/4/4640