Patent ID: 7816752
Filing Date: 2010-10-19
Classification: H01L

Abstract:
1. A solid state imaging device, comprising: an imaging region provided in an upper part of a silicon substrate, the imaging region including a photoelectric conversion region, said photoelectric conversion region including an upper layer, a middle layer and a lower layer; a device isolation at least partially surrounding the photoelectric conversion region, where the device isolation has a stepped shape including an upper part and lower part, and a width of the device isolation is smaller in the lower part than in the upper part and ungradually changes from the upper part to the lower part; a side wall layer covering a side and bottom surfaces of the device isolation and electrically connecting the upper layer and the middle layer; and a MOS transistor provided in the imaging region, the MOS transistor being electrically separated from the photoelectric conversion region by the device isolation, wherein a bottom surface of the upper layer is formed above a bottom edge of the upper part of the device isolation, the middle layer of the photoelectric conversion region is formed directly below at least a part of the bottom surfaces of the upper part of the device isolation, and the middle layer of the photoelectric conversion region is not formed directly below the bottom surface of the lower part of the device isolation.