Patent ID: 9165972
Filing Date: 2015-10-20
Classification: H01L

Abstract:
1. A semiconductor structure comprising a semiconductor layer of a first conductivity type, a photosensitive zone configured such that photogenerated charges may be accumulated in a first potential well; a region of a second conductivity type, formed in the semiconductor layer, for temporarily storing the photogenerated charges in a second potential well; a transfer gate between the region of the second conductivity type and the photosensitive zone for defining a potential barrier between the first and second potential wells during a non-transfer phase, and for eliminating the potential barrier between the first and second potential wells during a transfer phase; and a readout structure for reading out the temporarily stored photogenerated charges, which comprises a JFET, the gate of which is formed by the region of the second conductivity type, wherein the photosensitive zone is configured as a p-n photodiode which comprises a p-n junction, buried in the semiconductor layer, between a well of the second conductivity type, which is formed in the semiconductor layer, and a surrounding, adjoining portion of the semiconductor layer, and wherein the well of the second conductivity type extends as far as below the transfer gate so as to there adjoin a well of the first conductivity type which comprises a higher doping concentration than that of the semiconductor layer, the region of the second conductivity type and the JFET being embedded in the well of the first conductivity type.