Abstract: 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.

Abstract: In a charge transfer device including single-layer charge transfer electrodes including a p-type polycrystalline silicon layer and an n-type polycrystalline silicon layer, the sizes of the charge accumulation and potential barrier regions can be set to desired values and the height of potential barrier is produced with a desired reproducibility.A polycrystalline silicon layer is fabricated on a surface of a semiconductor substrate. With a photoresist layer 106 as a mask, ions of phosphorus are implanted thereinto so as to form a silicon oxide layer by liquid phase growth. Boron ions are then injected thereinto. The junction region between the n-type and p-type polycrystalline silicon layers is etched for the separation of the charge transfer electrodes.