Smart optical and image sensors fabricated with industrial CMOS/CCD semiconductor processes

Photosensitive elements with well-chosen geometry, combined with suitable analog and digital circuitry on the same CMOS/CCD chip, lead to 'smart image sensors' with interesting capabilities and properties. All our smart sensors were fabricated with commercially available multi-process wafer services of CMOS process, one of them with a buried-channel CCD option. Measurement of the optoelectronic properties of standard CMOS/CCD processes (wavelength-dependent quantum efficiency, lateral homogeneity of quantum efficiency/photo- conductivity, CCD charge transport efficiency, etc.) show excellent performance. The smartness that lies in the geometry is illustrated with a single-chip motion detector, a 3-D depth video camera, a single-chip planar distance sensor, and a sine/cosine (Fourier) transform sensor for fast optical phase measurements. The concept of problem-adapted geometry is also shown with a dynamic frame-transfer CCD whose pixel size and shape can be changed electrically in real-time through charge-binning. Based on the wavelength-dependent absorption of silicon, all-solid-state color pixels are demonstrated by properly arranging the available pn-junctions in the third (bulk) dimension. Moderate color measurement performance is achieved using an unmodified CMOS/CCD process, with a CIE general color-rendering index of Ra equals 69.5.