Integrated circuit devices and methods of manufacture

Abstract

A single photon avalanche diode （SPAD） image sensor including at least three device layers. The first device layer has an array of SPADs. The second device layer provides in-pixel circuitry for the SPADs. Row driver circuits， column readout circuits， and other circuits are in the third device layer or in a fourth device layer. The first device layer can be manufactured with a streamlined process that does not produce any transistors. The second device layer can be manufactured with a mature process technology that provides high voltage transistors. The third and optional fourth device layer can be manufactured with advanced process technology that provides high density transistors having lower operating voltages than are required for the in-pixel circuitry. This structure increases the number of SPAD pixels that can be provided per unit device area and is cost-effective.