Semiconductor device having a solid-state image sensor

摘要

A semiconductor device having a solid-state image sensor is provided in which the leakage current is less likely to occur. The surface portion of a P-type semiconductor substrate (1) is susceptible to various defects, which are likely to cause the leakage current. Accordingly an N-type buried channel layer (7a) is provided. While the potential is high in the vicinity of the surface of the P-type semiconductor substrate (1) where defects are present, the potential is minimized in the vicinity of the PN junction plane formed by the N-type buried channel layer (7a) and the P-type semiconductor substrate (1). Accordingly, when a transfer switch (M1) is operated, a channel is formed in the vicinity of this PN junction plane, so that a charge stored in an N-type source region (4a) of the photodiode (PD) can be transferred to an N-type drain region (5) without suffering leakage current.