Single-photon avalanche diode (SPAD) devices including a superlattice adjacent guard ring and related methods

Abstract

A single-photon avalanche diode (SPAD) device may include a semiconductor substrate having a first conductivity type, a deep well region in the semiconductor substrate having a second conductivity type different than the first conductivity type, and a multiplication region in the deep well region having the second conductivity type. The SPAD device may further include a central active region on the multiplication region and having the first conductivity type, a guard ring surrounding the central region and the multiplication region and having the first conductivity type, and a superlattice layer adjacent an interface between the multiplication region and the guard ring. The superlattice layer may include stacked groups of layers, with each group of layers comprising stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions.

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