| 摘要 |
<p>A back-illuminated CCD sensor comprises a substrate of one polarity type, buried charge transfer channels 102 of the opposite polarity type, control electrodes 100 fabricated on the front face of the sensor for transporting charge along the channels, the bias on a first bias connection on a channel stop region 113 of the first polarity type surrounding the sensor area and the bias of the control electrodes being such that the channels are surface pinned. While this would normally result in only a shallow depletion layer under the buried channels and hence poor spatial resolution, the invention provides a guard diode ring 115 surrounding the channel stop region, the guard diode region being of the same polarity type as the channels, and the depletion region under the guard diode ring spreading to meet 117 that beneath the buried channels 102, thereby enabling the front surface bias 114 and rear surface bias 111 to be maintained at different potentials, thus permitting the depletion region associated with the channels to be fully depleted or adjusted to a desired depth.</p> |
