30 results about "Dark count rate" patented technology

Avalanche photodiodes are provided, wherein the APDs provide both high optical coupling efficiency and low dark count rate. The APDs are formed such that their cap layer has an active region of sufficient width to enable high optical coupling efficiency but the APD still exhibits a low dark count rate. These cap layers have a device area with an active region and an edge region, wherein the size of the active region is substantially matched to the mode-field diameter of an optical beam, and wherein the size of the edge region is made small so as to reduce the number of defects included. These APD designs maintain a substantially uniform gain and breakdown voltage, as necessary for practical use.

The SPAD device comprises a single-photon avalanche diode and a further single-photon avalanche diode having breakdown voltages, the single-photon avalanche diodes being integrated in the same device. The breakdown voltages are equal or differ by less than 10%. The single-photon avalanche diode is configured to enable to induce triggering or to have a dark count rate that is higher than the dark count rate of the further single-photon avalanche diode.

The invention provides a low-dark-count-rate CMOS SPAD photoelectric device. A P-well layer is added based on a routine P+ / N-well type SPAD structure. The P-well layer is arranged between the P+ layerand the N-well layer. Furthermore, an N-well clearance is utilized as a virtual protecting ring of the structure; namely N-wells are added at two sides of a PN junction, wherein the structure is shown in the attached figures of an abstract. An incident photon is incident into the device and is attracted at the central N well, and furthermore a photon-generated carrier is generated. The P-well layer and the N-well layer are utilized at two sides of the PN junction. Hereon an avalanche junction is a P-well / N-well junction. Because the avalanche junction is a lightly doped avalanche junction, width of a depletion region increases, and probability of interband tunneling of the carries is reduced, thereby reducing the dark counting rate. Furthermore the virtual protecting ring is used for suppressing edge breakdown of the PN junction. The forming principle of virtual protection is characterized in that transverse diffusion exists between adjacent N-wells and therefore the N- virtual protecting ring is formed at the PN junction. The low-dark-count-rate CMOS SPAD photoelectric device is designed at two aspects of the protecting ring and the depletion region width, dark current of the device is reduced, thereby reducing the dark count rate.