<title>CCD/CMOS process for integrated image acquisition and early vision signal processing</title>

Abstract

The novel technology resulting from the merger of a Charge Coupled Device (CCD) capability with a Complementary Metal Oxide Semiconductor (CMOS) process allows a large class of charge-based circuits to be integrated with CMOS circuits. CCD's can perform image-to-charge conversion, spatial shifting, analog storage, and many other linear signal processing functions necessary for vision. This capability, in conjunction with an analog CMOS process, should prove to be a very useful technology in implementing an integrated early vision system. This paper describes the technology development necessary for the integration of a four phase, buried-channel CCD capability in an existing 1.75 micron CMOS process. This enhancement requires an additional implant step, a second gate oxidation, a second level of polysilicon, and an additional etching step, adding two more lithographic levels to the 11 mask CMOS process. In addition, this process allows the fabrication of poly-to-poly capacitors with low voltage and temperature coefficients that are useful in many analog MOS applications. The process utilizes a 23nm gate dielectric for high transconductance and a 42nm poly-to-poly capacitor insulator. The poly-oxide provides excellent electrical isolation, and results in a C0 value which allows for good component matching. Experimental results are presented.

Analog VLSI systems for image acquisition and fast early vision processing

“…Horn, Lee, Poggio, Sodini, and Wyatt, principal investigator. The completed designs to date include seven different analog chips for image filtering and edge detection [1][2][3], moment extraction to determine object position and orientation [4][5][6], image smoothing and segmentation [7][8][9][10], depth determination from stereo image pairs [11], accurate depth determination jointly from imperfect depth and slope data [12], and camera motion determination [13], plus other chips to test novel circuit designs or processing methods [7,14,15]. Some of these projects are now complete, while others are in various stages of testing, redesign, or refabrication.…”