8.0 Conclusion

Using CCD Transfer Curves to absolutely characterize and calibrate all of the CCD performance parameters necessary for high performance night vision applications, two high frame rate, low noise, back-illuminated CCDs manufactured using PixelVision’s Sandbox^TM CCD foundry service were described. The 2048 x 1024 element, split frame transfer PlutoIII CCD design and characterization was used to demonstrate the ability of large area back-illuminated CCDs to operate at video rates with high dynamic range and with low noise. Both 9-micron square pixel and 12-micron square pixel versions of the PlutoCCD CCD were tested. A split frame transfer design with four output amplifiers was chosen as a baseline. All of the CCD parameters tested exhibited low light level imaging superior to conventional night vision technologies. Excellent cosmetic quality, dynamic range exceeding 14 bits, linearity better than one percent, negligible dark current at video rates, nearly ideal charge transfer efficiency, and low readout noise were achieved.

Due to manufacturing tolerances, the 4.5 electrons rms. noise floor of the PlutoCCD CCD represents a practical lower limit for large area devices. To further improve the sensitivity of back-illuminated CCDs for low light level imaging, architectures with greater than four amplifiers will be required to reduce the bandwidth of each analog channel. To demonstrate the performance and manufacturability of multiple output CCDs, the forty output amplifier ADAPTIII CCD was tested. On a majority of the devices manufactured, all of the forty amplifiers were shown to have a noise floor of approximately 4 electrons rms. or better.

Having successfully optimized the designs and processes of high resolution, large area CCDs and multiple amplifier designs, the next generation of Sandbox^TM will build upon the successes of their predecessors. The Kino, 2048 x 1024, 8-output amplifier CCD has been manufactured on PixelVision, Inc.’s SandboxIV foundry run. The device is currently being tested. Low-light-level CCD designs with larger formats and with 32 and 64 output amplifiers will follow.