Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Solid-state image sensor having a substrate with an impurity concentration gradient
 A solid-state image sensor comprises a semiconductor substrate, a photoelectric conversion portion formed above the semiconductor substrate, and noise cancelers each formed, adjacent to the photoelectric conversion portion, on the semiconductor substrate through an insulating film, for removing noise of a signal read from the photoelectric conversion portion, wherein the semiconductor substrate has a conductive type opposite to a conductive type of a charge of the signal, and has a first region where concentration of impurities for determining the conductive type is high and a second region where concentration of the impurities on the first region is low. 
Kabushiki Kaisha Toshiba
Y H
Y02E H01L
additional inventional
Hirofumi Hidetoshi Ikuko Tetsuya Hisanori
Yamashita Nozaki Inoue Yamaguchi Ihara