Vertical charge transfer type photon demodulator and working method thereof

Abstract

The invention relates to a vertical charge transfer type photon demodulator and a working method thereof. The upper surface of a semiconductor is provided with a modulation-demodulation part, and the lower surface of the semiconductor extends to the bottom of a substrate to form a photosensitive part; the photosensitive part converts photons into photon-generated carriers, photo-generated electron-hole pairs are separated by using a vertical electric field, and electrons or holes are vertically transported to the surface of a semiconductor for optical signal demodulation. The two charge collection regions are 1.8 V, the modulation switch I is connected with 1.2 V, the modulation switch II is connected with 0V, the substrate electrode is grounded, a transverse electric field is generated at the upper part of the semiconductor substrate, and a vertical electric field is generated in other regions; photons are absorbed by the semiconductor and excite an electron-hole pair, the electron-hole pair is separated under the action of an electric field, and electrons move upwards to the surface of the semiconductor; and under the action of a transverse electric field, the electrons further move to the vicinity of a charge collection region and enters a depletion region generated by the electrons through diffusion to form a light current signal. The photon demodulator is small in size and high in sensitivity and quantum efficiency.

Description

technical field [0001] The invention relates to a vertical charge transfer photon demodulator, and also relates to a working method of the vertical charge transfer photon demodulator, belonging to the technical field of photon demodulators. Background technique [0002] ToF is widely used as a method of optical ranging, and the main purpose of TOF devices is to be able to read signals with fixed frequency and fixed phase, and a high-speed sensor is required to read the required integration time. The signal within, that is, the sensor has a better response to high-frequency signals. The usual practice is to feed the signal to the desired readout node at the desired time and to the other node at the opposite time. [0003] The CAPD device invented by Sony in patent US 8,294,882 B2 has simple process, high sensitivity, high quantum efficiency, and fast speed. Shallow, greatly reducing efficiency. The PMD technology adopted by Infineon uses photo-gate to generate depletion re...

AI Technical Summary

Problems solved by technology

[0003] The CAPD device invented by Sony in patent US 8,294,882 B2 has simple process, high sensitivity, high quantum efficiency, and fast speed. Shallow, greatly reducing efficiency

The PMD technology adopted by Infineon uses photo-gate to generate depletion region for photosensitivity. There is also the problem that as the pixel size shrinks, the depletion region becomes shallower, which eventually leads to a decrease in quantum efficiency.

There is still no small-sized ToF device that can maintain high sensitivity and quantum efficiency

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