Solid state image sensor having an unnecessary electric charge exhausting section formed adjacent to a horizontal electric charge transfer section, and a method for manufacturing the same

摘要

A solid state image sensor having an unnecessary electric charge exhausting section formed adjacent to a horizontal electric charge transfer section, comprises an N-- semiconductor substrate 1 having a P-well layer 2 formed on a principal surface thereof. On the P-well layer 2, there is formed a horizontal electric charge transfer section adjacent to one end of each of a number of vertical electric charge transfer sections. A transfer channel 15A of each vertical electric charge transfer section and an electric charge barrier region 5A of a transfer channel of the horizontal electric charge transfer section are formed of an N-type semiconductor region, and an electric charge storing region 6A of the transfer channel of the horizontal electric charge transfer section are formed of an N+ semiconductor region. A potential barrier region 11A is formed at the side of the horizontal electric charge transfer section opposite to the vertical electric charge transfer sections. The unnecessary electric charge exhausting section is constituted of an N++ semiconductor region formed at the side of the potential barrier region 11A opposite to the horizontal electric charge transfer section. The electric charge barrier region 5A and the potential barrier region 11A are formed simultaneously and have the same impurity concentration.