SBIR-STTR Award

There is a distinct need to replace the current Gen III image intensifier imaging system with an all solid-state low light level camera. Between the two potential silicon solid-state image sensor technologies, the CCD is the preferred choice since it generally has higher QE, lower dark current and better uniformity than the state-of-the-art CMOS imager. To meet the performance requirements under overcast starlight level conditions with no or minimum cooling, the dark current of a conventional CCD needs to be further reduced. In addition, given the high dynamic that the camera must support, a conventional CCD (even with anti-blooming structure) may have a potential smear problem where a bright spot in the image causes smearing in the associated column during the vertical register transfer time. The smear will result in extra electron injection into other pixels within that column, causing extra shot noise that degrades the image quality. In this work we will design a high performance, interline frame transfer CCD that will achieve 10pA/cm? dark current, or less than 2 electrons per pixel per frame. The CCD architecture will have minimum smearing even when the bright region in the image is 100 times stronger than the sensor saturation level

There is a need to complement the current Gen III image intensifier imaging system with a solid-state low light level camera that is better optimized for remote viewing applications. A silicon-based solution is an ideal candidate for low light imaging because of its high quantum efficiency, low dark current, and excellent uniformity. However, to meet performance requirements under overcast starlight conditions with minimum or no cooling, the total noise of a conventional CCD or CMOS camera is prohibitive. A hybrid focal plane with CCD retina coupled to a CMOS readout integrated circuit has been shown to have sufficiently low noise so as to offer a true solid-state night vision capability. In order to improve its utility as a night imaging sensor, the CCD must be designed to eliminate smear, which is the result of the sensor being illuminated during image readout. To achieve this performance, we will design a high performance, split-frame interline transfer (split FIT) CCD imager that will achieve 10pA/cm2 dark current and less than 2 electrons readout noise per pixel per frame at room temperature. The split FIT CCD architecture is absolutely necessary for low smear performance.

Keywords:
Solid State Low Light Level Tv Camera, Interline Transfer Ccd, Roic, Night Vision, Smear And Blooming, Active Reset Cmos