Spectral response of CMOS photosensors

We report on CMOS compatible photosensors fabricated with a standard CMOS process. Two different types of diodes, a PMOS-FET and a vertical pnp bipolar transistor were investigated. Absolute sensivities in a spectral range from 400 nm to 900 nm wavelength were compared. Furthermore, the behaviour of a sensor system consisting of a diode, an integrated logarithmic amplifier and a temperature compensation will be reported. By use of an external optical filter a photometric sensor behaviour is measured down to 20 mlx intensity for a sensitive area of 0.34 qmm. This filter is replaced by a deposited thin film stack, working as an integrated interference filter. Fabrication process and experimental results hereon will be presented.