Near-infrared CCD image sensors

Louise Davis

ON Semiconductor is enhancing imaging performance in demanding industrial applications with technology that improves the near-infrared sensitivity of CCD image sensors.

The 8 megapixel (MP) KAI-08052 image sensor, the first device in ON Semiconductor’s CCD portfolio to leverage this new technology, provides up to twice the sensitivity in near-infrared (NIR) wavelengths as the company’s standard Interline Transfer CCD pixel design. This enhanced sensitivity can be critical in applications such as scientific and medical imaging, where samples emit or fluoresce in NIR wavelengths; or in machine vision and intelligent transportation systems (ITS), where NIR illumination is often used to better examine an object or to isolate a vehicle’s license plate.

The new CCD pixel design used in the KAI-08052 extends the electron capture region deeper in the silicon to better capture electrons generated by long wavelength photons. This deeper pixel well improves detection of NIR wavelengths by up to a factor of two depending on the specific wavelength studied.  And since the well structure also isolates the photodiodes from each other, this increase in NIR sensitivity comes without any reduction in image sharpness (modulation transfer function, or MTF).

The KAI-08052 is available in a RoHS-compliant CPGA-67 package in Monochrome, Bayer Colour, and Sparse Colour configurations, and is fully pin compatible with the existing KAI-08051 image sensor as well as a full family of 5.5 µm and 7.4 µm CCD image sensors, enabling camera manufacturers to quickly adopt the new device.