Abstract
Along with the improvement of imaging technology, photodetectors with high sensitivity became popular. However, Single Photon Avalanche diode(SPAD), which has so many advantages such as high sensitivity and being easy to be integrated with quenching circuit, was not paid close attention by people. The reason is the noise made by SPAD. But its excellent sensing capability is what we need. If we can solve the problems of noise, it will be a big improvement for the application of SPAD. This work, contains two parts. The first part is the design of a SPAD applicable in near infrared rays with low breakdown voltage about 10 volts. We used the junction between P-well and Deep N-well, because the concentration of P-well is higher and the junction depth is deep. The measured results show that the breakdown voltage of the SPAD is about 11.8-11.9 volts and the peak of responsivity is located 830nm wavelength. The results are matched with what we expected. The second part of the thesis is the application of the SPAD photodetector. We designed a quenching circuit to recover the operating voltage to breakdown voltage. Furthermore, by adjusting the resistance and capacitance in the quenching circuit we can reduce the noise in SPAD photodetector. The measured results show that the SPAD can be integrated with the quenching circuit and is functional. However, because of some improper design in the circuit, the quenching circuit was not able to reduce the after pulsing noise.