| 摘要 |
PURPOSE:To reduce the floating capacity of a floating diffusion amplifier type charge detector, and to improve sensibility by narrowing the width of a first conductivity type impurity region in a floating diffusion region up to the same extent as the width of a contact hole and forming a high-concentration impurity region under the contact hole. CONSTITUTION:In a charge detector 30, an N-type impurity region 31 continuing to a buried channel 12 is shaped, and the width R of the buried channel 12 is made the same as or smaller than that H of a contact hole 23. A high- concentration impurity region 32 is formed through the ion implantation of an N-type impurity (arsenic As<+75> or phosphorus P<+31>) from the contact hole 23. Accordingly, the width W of the impurity region 31 and the high- concentration impurity region 32 is reduced up to the same extent as the width H of the contact hole 23, thus lowering the capacity of a floating diffusion region composed with the high-concentration impurity region 32, then improving the sensibility of detection.
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