Patent ID: 7705381

Claim:
A MOS solid-state image sensing device comprising: a photoelectric conversion unit which includes, sequentially from a light incident side, a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type which can store signal charge and is opposite to the first conductivity type, a third semiconductor region of the second conductivity type having an impurity concentration lower than that of said second semiconductor region, and a fourth semiconductor region of the first conductivity type; a floating diffusion region of the second conductivity type having an impurity concentration higher than that of the third semiconductor region; a transfer MOS transistor for transferring electrical charges generated at said photoelectric conversion unit to said floating diffusion region, said transfer MOS transistor comprising a part of said photoelectric conversion unit, said floating diffusion region as a drain region and a transfer gate electrode disposed between said photoelectric conversion unit and said floating diffusion region; an amplifying element for amplifying a signal based on electrical charges of said floating diffusion region and outputting an amplified signal; an element isolation region made of an insulating material and disposed between said photoelectric conversion unit and an other photoelectric conversion unit; a fifth semiconductor region of the first conductivity type disposed under said transfer gate electrode; and a sixth semiconductor region of the first conductivity type disposed under said element isolation region, wherein said fourth semiconductor region and said fifth semiconductor region are disposed to be in contact with each other, wherein said fourth semiconductor region and the sixth semiconductor region are disposed continuously, and wherein a potential barrier to the electrical charges is provided by each of said fourth, fifth, and sixth semiconductor regions.