Patent ID: 8325221
Filing Date: 2012-12-04
Classification: H01L,H04N

Abstract:
1. A separation type unit pixel having a 3D structure for an image sensor comprising: a first wafer including a photodiode containing impurities having an impurity type opposite to that of a semiconductor substrate and a pad for transmitting photoelectric charge of the photodiode to outside; a second wafer including a pixel array region in which transistors except the photodiode are arranged regularly, a peripheral circuit region having an image sensor structure except the pixel array, and a pad for connecting pixels with one another; and a connecting pad connecting the pad of the first wafer and the pad of the second wafer, wherein the first wafer comprises: a semiconductor substrate which contains specific impurities for forming a photodiode; a first transparent buffer layer which is inserted between a color filter and the semiconductor substrate to facilitate formation of structures and to improve light transmittance; a photodiode which contains impurities having an impurity type opposite to that of the semiconductor substrate; and a pad transmitting photoelectric charge of the photodiode to outside.