| 摘要 |
PURPOSE:To maintain time response characteristics stably, and to monitor the mean output level of a photosensitive picture element group precisely by forming a stepped section deepening toward a floating diffusion region from a photosensitive section for monitor to the potential of an output gate. CONSTITUTION:Impurity concentration in a region 11a on the photosensitive section 8 side for monitor is made lower than that in a region 11b on the floating diffusion region 9 side, and the potential V11a of the region 11a is made shallower than that V11b of the region 11b when the same gate voltage VG is applied to output gate electrodes 12a, 12b. That is, potential V11b is directly subject to the effect of a potential change in the region 9, but potential V11a is not affected by it and is kept constant. Accordingly, time response characteristics at a time when signal charges DELTAQ are outputted to the region 9 through sections under the electrodes 12a, 12b from the photosensitive section 8 are determined approximately by the shape of the electrode 12a, stable time response characteristics are obtained on an output even when the channel length L2 of an output gate 11 is short, and a device can be made to correspond accurately to the mean level of the quantity of charges outputted from a photosensitive picture element group stably. |
