Patent ID: 8558292

Claim:
A method for fabricating an active pixel sensor comprising a sensor wafer and a support circuit wafer, wherein the sensor wafer includes two or more interconnects connected to readout circuitry of an array of active pixel regions included on the sensor wafer, wherein the array of active pixel regions includes a first active pixel and a second active pixel, wherein each active pixel includes a photodetector, a transfer gate, and a charge-to-voltage conversion mechanism, and wherein the support circuit wafer includes a plurality of interconnects connected to support circuitry included on the support circuit wafer, the method including: forming a color filter array and a plurality of microlenses over a surface of the sensor wafer; applying a protective layer over the plurality of microlenses, the color filter array, and the surface of the sensor wafer prior to attaching the sensor wafer to a handle wafer; attaching the sensor wafer to the handle wafer using a removable interface layer; backside thinning the sensor wafer to a given thickness; attaching the support circuit wafer to the sensor wafer, including electrically connecting a plurality of inter-wafer connector wires between the two or more interconnects of the sensor wafer with corresponding interconnects of the support circuit wafer, wherein the electrical connections with the plurality of inter-wafer connector wires is made at a perimeter edge of the array of active pixel regions, wherein a charge-to-voltage mechanism of the first active pixel and a charge-to-voltage mechanism of the second active pixel are both connected to a single gate of a source follower amplifier transistor included in the support circuit wafer by way of an inter-wafer connector; and separating the handle wafer from the sensor wafer.