Abstract: A pixel for an imager is disclosed that includes at least one electron multiplication (EM) gain stage configured in a loop and electrically coupled to a charge collection region and a charge readout region, the charge collection region being configured to generate a charge packet, the EM gain stage being configured to amplify the charge packet by impact ionization and to circulate the charge packet a predetermined number of times in one direction around the loop, the charge readout region being configured to receive the amplified charge packet and convert the amplified charge to a measurable signal. The at least one EM gain stage, the charge collection region, and the charge readout region can be formed monolithically in an integrated circuit. The pixel can be manufactured using a CMOS process. The pixel can further include a second EM gain stage formed in the integrated circuit to increase the amount of amplification around the loop.

Abstract: A pixel for an imager is disclosed that includes at least one electron multiplication (EM) gain stage configured in a loop and electrically coupled to a charge collection region and a charge readout region, the charge collection region being configured to generate a charge packet, the EM gain stage being configured to amplify the charge packet by impact ionization and to circulate the charge packet a predetermined number of times in one direction around the loop, the charge readout region being configured to receive the amplified charge packet and convert the amplified charge to a measurable signal. The at least one EM gain stage, the charge collection region, and the charge readout region can be formed monolithically in an integrated circuit. The pixel can be manufactured using a CMOS process. The pixel can further include a second EM gain stage formed in the integrated circuit to increase the amount of amplification around the loop.

Abstract: An actively driven, metal light shield for shielding floating diffusion regions and amplifiers of multi-port CCD or CMOS imager arrays from unwanted light is disclosed. The driven shield overlies one or more floating diffusion regions and buffer amplifiers lying outside the active pixel area of the imager (non-imaging area), which is also protected from unwanted light by a fixed potential shield. The driven shield is directly electrically connected to a source node of a source-follower amplifier stage, i.e., the buffer amplifiers non-inverting output. The fixed potential shield is electrically connected to a DC voltage capable of eliminating charging of the fixed potential shield and substantially overlies the non-imaging area and at least partially overlapping the driven shield.