Electric-field-drive single photon avalanche diode with barrier enhancement for fluorescence detection

Abstract

Single photon avalanche diodes(SPAD) are widely used in fluorescence detection. The fluorescent optical fiber temperature sensor has strict regulations on the photoelectric conversion capability and spectral response range of the detector. Therefore, in response to the above problems, this paper proposes an N-type buried electric-field-drive guard ring SPAD(NEGR-SPAD) device with a wide-spectral-response. In addition, NEGR-SPAD is compared and analyzed with dummy-gate guard ring SPAD(DGR-SPAD) and traditional gate-controlled guard ring SPAD(TGGR-SPAD). Technology-Computer-Aided-Design(TCAD) simulation is used to verify the photoelectric conversion mechanism of the device. The three types of SPAD are manufactured based on the 0.18 μm BCD process. Under the excess bias voltage of 0.5V, the NEGR-SPAD can achieve a 37.4% photon detection probability(PDP) in the wavelength range of 440 nm–700 nm. The PDP peak (46.1%) of the device appears at 480 nm. The test results verify that the device has a wide-spectral-response. Furthermore, the dark count rate(DCR) per unit area of NEGR-SPAD is 1.28 Hz/μm2(temperature: 22 °C, excess bias voltage: 1V).