Current assisted photonic mixing demodulator implemented in 0.18μm standard CMOS technology

CMOS image sensors integrate the image processing circuitry on the same chip as the light sensitive elements. Recently, lots of effort has been concentrated to create a standard CMOS photonic demodulator. A CMOS based current assisted photonic mixing demodulator is described in this paper. As a test vehicle, 10×10 pixel arrays in two different geometries have been fabricated with a 0.18μm CMOS technology. Remarkably small pixel size of 10×10 μm2 has been achieved. Preliminary experimental results demonstrate a good DC charge separation efficiency close to 100% and good demodulation capabilities up to 35MHz. The measurement results are compared to the performance of two different device array structures. These test devices represent the first step towards integrating a high resolution TOF based 3D CMOS image sensor.