OMNIVISION TURNS DIGITAL IMAGING WORLD UPSIDE DOWN

OMNIVISION TURNS DIGITAL IMAGING WORLD UPSIDE DOWN

OmniVision Technologies has launched its OmniBSITM architecture, a novel sensor design that adopts a radically different approach to traditional CMOS image sensor technology. Using backside illumination (BSI), OmniBSI enables OmniVision to continue offering improved image quality while extending its pixel roadmap down to 0.9 micron pixels, which is the key to continued miniaturization of digital imaging technology.

BACKSIDE ILLUMINATION TECHNOLOGY IMPROVES IMAGE QUALITY, ENABLES DESIGN SHRINKS DOWN TO 0.9 MICRON PIXELS

BSI methodology involves turning the CameraChip sensor upside down so that it collects light through what was previously the backside of the sensor, the silicon substrate. This approach differs from conventional front side illumination (FSI) image sensors, where the amount of light reaching the photosensitive area is limited, in part, by the multiple metal and dielectric layers required to enable the sensor to convert photons into electrons.

The FSI approach can block or deflect light from reaching the pixel, ultimately reducing the fill factor and causing additional problems, such as cross talk, between pixels. BSI reverses the arrangement of layers so that the metal and dielectric layers reside below the sensor array, providing the most direct path for light to travel into the pixel. This novel approach optimizes light absorption.