Single photon avalanche diode and single photon avalanche diode array

Abstract

The invention provides a single photon avalanche diode. The single photon avalanche diode comprises an N-type semiconductor buried layer, an active region and an N-type stack layer. The active region comprises a first P-type semiconductor well layer, a first N-type semiconductor well layer, a second P-type semiconductor well layer, two anodes and a P-type epitaxial layer. The first P-type semiconductor well layer is disposed on the N-type semiconductor buried layer, and the first N-type semiconductor well layer is disposed on the first P-type semiconductor well layer. The second P-type semiconductor well layer is disposed on the first N-type semiconductor well layer, and the two anodes are disposed on two opposite sides of the second P-type semiconductor well layer. The P-type epitaxial layer is connected with the first P-type semiconductor well layer and the second P-type semiconductor well layer. The N-type stack layer is disposed beside the active region and on the N-type semiconductor buried layer. A single photon avalanche diode array is also provided.

Description

technical field [0001] The present invention relates to a photodiode and a photodiode array, and in particular to a single photon avalanche diode (SPAD) and a single photon avalanche diode array. Background technique [0002] After the single photon avalanche diode is irradiated by light, the electrons and holes are separated to form a photocurrent. When the electrons separated from the electric holes enter the electric field acceleration region (that is, the avalanche region) at the PN junction (p-n junction), the electrons are greatly accelerated by the electric field and hit other atoms, causing other atoms to dissociate more electrons, forming a breakdown current (avalanche current). The current value of the breakdown current is much larger than the original photocurrent, which can effectively improve the sensing sensitivity. [0003] Single-photon avalanche diodes can be applied to time-of-flight ranging devices (ToF ranging devices) or LiDARs, which can calculate the...

AI Technical Summary

Problems solved by technology

In this case, photoelectrons are more likely to drift to a position outside the avalanche region, resulting in a loss of photon detection probability (PDP)

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