초록 ▼

Back-illuminated CCD imagers of interline transfer type are made possible by deep, highly doped implant regions which bury the CCDs with respect to the back-illuminated surfaces of the imager substrates. Transfer smear caused by photoconversion in the CCD charge transfer channels must be suppressed

Back-illuminated CCD imagers of interline transfer type are made possible by deep, highly doped implant regions which bury the CCDs with respect to the back-illuminated surfaces of the imager substrates. Transfer smear caused by photoconversion in the CCD charge transfer channels must be suppressed in certain of these back-illuminated CCD imagers of interline transfer type, and suitable suppression methods are described.

대표청구항 ▼

A CCD imager of interline transfer type comprising: a thinned semiconductive substrate having opposed first and second surfaces separated by a bulk; a parallel array of CCD charge transfer channels arranged within said bulk along a portion of said first surface of said semiconductive substrate oppos

A CCD imager of interline transfer type comprising: a thinned semiconductive substrate having opposed first and second surfaces separated by a bulk; a parallel array of CCD charge transfer channels arranged within said bulk along a portion of said first surface of said semiconductive substrate opposed by a portion of the second surface of said semiconductive substrate that is adapted for illumination by an optical image responsive to which illumination charge carriers are generated within said semiconductive bulk; sets of gate electrodes crossing said CCD charge transfer channels for defining successive charge transfer stages in each of said charge transfer channels, said charge transfer stages being separated by electrically insulative layers from each other and the first surface of said substrate, said sets of gate electrodes being receptive of clocking signals selectively supplied to them to transfer charge packets from one charge transfer stage to the next in each of said charge transfer channels; photocharge collecting regions in said semiconductive substrate spaced from said second surface by a substantial portion of said bulk and associated with at least selected ones of said charge transfer stages; means for selectively transferring at specified times charge packets from each of said photocollecting regions to its associated charge transfer stage; means, sensing the amplitudes of charge packets transferred out of the final charge transfer stage of each CCD charge transfer channel in said parallel array, for generating successive samples of a raster scanned video signal, said video signal having field retrace intervals therein, and said video signal having field trace intervals therein comprising interleaved line trace intervals and line retrace intervals; and respective implantation regions disposed in said semiconductive substrate between its second surface and each of said CCD charge transfer channels in said parallel array, burying those charge transfer channels respective to the second surface of said semiconductive substrate, for causing charge generated by photoconversion between that second surface and each said charge transfer channel to diffuse towards nearby photocharge collecting regions and thus improve the fill factor of said CCD imager.