A CMOS process compatible color sensor using wavelength dependent absorption depth

Principles of a filterless, color imaging sensor are presented. The color detection mechanism is based on the wavelength-dependent absorption-depth, and hence electron-hole pair generation, in mono-crystalline silicon. The Lorentz force is used to deflect the photo-induced carriers towards the chip surface. The moving charges are collected at different positions depending on their initial depth and cell geometry, thus, providing color separation without filtering. A simple geometrical analysis proves the feasibility of the concept for medium magnetic field intensity. The sensor is conceived and fabricated in standard CMOS processes and its detection mechanism is proven to be independent of supply voltage.