Open Poly CCD

The Open Poly or open-electrode CCD is a front illuminated CCD with a modified electrode structure to enhance the UV sensitivity. Some of the polysilicon gate structure, which absorbs UV radiation is removed, leaving a large part (40%) of the pixel area uncovered.
See Figure 1.

QE for the Open Poly front illuminated CCDTo control the surface potential in the open area, a shallow p+ implant is located in the buried channel. This pins the local surface potential to that of the substrate. Thus the device operates in a similar manner to a conventional front illuminated CCD at a 40% reduced full well capacity. The QE of the device is increased through the spectral range and is roughly a factor of 2 times better in the UV vs. Lumogen coated devices, while exhibiting none of the etaloning behavior of back illuminated CCD’s beyond 800 nm. We offer the Spec-10 : 256E 1024 x 256 pixel spectroscopy CCD in open-electrode technologie .


p+ implant located in the buried channel
Figure 1