Depth image sensor with always-depleted photodiodes

• Main Authors: Nagaraja, Satyadev Hulikal, Bamji, Cyrus Soli, Oh, Minseok
• Format: Patent
• Language: English
• Published: 21.02.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Examples are disclosed that relate to the use of an always-depleted photodiode in a ToF depth image sensor. One example provides a method of operating a pixel of a depth image sensor, the method comprising receiving photons in a photocharge generation region of the pixel, the photocharge generation region of the pixel comprising an always-depleted photodiode formed by a doped first region comprising one of p-doping or n-doping and a more lightly-doped second region comprising the other of p-doping or n-doping. The method further comprises, during an integration phase, energizing a clock gate for a pixel tap, thereby directing photocharge generated in the photocharge generation region to an in-pixel storage comprising a capacitor, and in a readout phase, reading charge out from the in-pixel storage.