A 1k-pixel 3D CMOS sensor

A solid-state three-dimensional Time-of-Flight sensor is presented consisting of 32 times 32 range pixels based on Current-Assisted Photonic Demodulation (CAPD). Each pixel measures 30 mum times 30 mum and consists of 6 transistors and a differential current-assisted photonic demodulator, yielding a Fill-Factor of 66%. The sensor is implemented in 0.35 m standard CMOS technology without optical optimization steps, while still achieving a 0.2 A/W responisivity at 870 nm. Range-finding is achieved through Modulated Wave Time-of-Flight using a modulation frequency of 20 MHz. The range performance of this sensor is discussed and TOF measurements of a prototype camera-system using this sensor are presented.