公开(公告)号：JPH11121729A

公开(公告)日：1999-04-30

申请号：JP22878198

申请日：1998-08-13

Applicant: IBM

Inventor： HOOK TERENCE B ,  JEFFREY B JOHNSON ,  ROBERT LEIDY ,  HONSUN P WON

IPC: H01L27/146 ,  H01L31/10

Abstract: PROBLEM TO BE SOLVED: To provide a photosensitive device of which the blue color light and red color light sensitivities are improved. SOLUTION: An active pixel sensor photosensitive device is provided with an extremely thin virtual pinning layer formed by inversing the semiconductor material on the surface of a photosensitive region. This thin pinning layer improves the blue color light response. The inverted pinning layer is preferably formed by connecting a negative potential supply to a transparent conductive layer 42 made of indium tin oxide deposited on the most part of a photosensitive region 40. The conductive layer 42 is insulated from the photosensitive region 40 by a thin insulating layer 44. The connection to the pinning layers is performed through a coupling region 50 formed in a region neither covered with the conductive layer 42 nor the insulating layer 44. In such a constitution, preferably a germanium.silicon-made strain layer 36 is formed deeply in the photosensitive layer 40 thereby enabling the red color response to be improved and decreasing the depth of the photosensitive region 40. Besides, the strain layer 36 is provided with a corrected band gap thereby increasing the absorption factor of red color light.