Abstract: A CMOS image sensor with a many million pixel count. Applicants have developed techniques for combining its continuous layer photodiode CMOS sensor technology with CMOS integrated circuit lithography stitching techniques to provide digital cameras with an almost unlimited number of pixels. A preferred CMOS stitching technique exploits the precise alignment accuracy of CMOS stepper processes by using specialized mask sets to repeatedly produce a single pixel array pattern many times on a single silicon wafer with no pixel array discontinuities. The single array patterns are stitched together lithographically to form a pixel array of many million pixels. A continuous multilayer photodiode layer is deposited over the top of the many million pixel array to provide a many million pixel sensor with a fill factor of 100 percent or substantially 100 percent.

Abstract: A method for wafer-to-wafer bonding of a sensor readout circuitry separately fabricated with a silicon substrate to a photodiode device made of non-silicon materials grown from a separate substrate. In preferred embodiments the non-silicon materials are epitaxially grown on a silicon wafer. The bonding technique of preferred embodiments of the present invention utilizes lithographically pre-fabricated metallic interconnects to connect each of a number of pixel circuits on a readout circuit wafer to each of a corresponding number of pixel photodiodes on a photodiode wafer. The metallic interconnects are extremely small (with widths of about 2 to 4 microns) compared to prior art bump bonds with the solder balls of diameter typically larger than 20 microns. The present invention also provides alignment techniques to assure proper alignment of the interconnects during the bonding step.

Abstract: A MOS or CMOS based active pixel sensor with special sampling features to substantially eliminate clock noise. The sensor includes an array of pixels fabricated in or on a substrate, each pixel defining a charge collection node on which charges generated inside a photodiode region are collected, a charge integration node, at which charges generated in said pixel are integrated to produce pixel signals, a charge sensing node from which reset signals and the pixel signals are sensed. In preferred embodiments the sensor includes a continuous electromagnetic radiation detection structure located above the pixel circuits providing a photodiode region for each pixel. The sensor includes integrated circuit elements adapted to maintain voltage potentials of the charge integration nodes substantially constant during charge integration cycles. The sensor also includes integrated circuit elements having electrical capacitance adapted to store charges providing an electrical potential at the charge integration node.