EQR SiPM with P-on-N diode configuration

The silicon photomultiplier (SiPM) with epitaxial quenching resistor (EQR) is an emerging and developing technology that has recently attracted the interest from the research community. It has characteristics of a continuous low-resistance cap layer and integrated quenching resisters in epitaxial silicon layer, which makes it possible to increase microcell density or reduce microcell size, thus obtaining large dynamic range and high photon detection efficiency (PDE) simultaneously. Results published show that the EQR SiPM with N-on-P diode configuration had relatively low PDE at peak wavelength of 480 nm as 16%. This paper reported the EQR SiPM with P-on-N diode configuration having active area of 3 × 3 mm² and cell density of 10,000/mm² (total 90,000 pixels). It was characterized with gain of 2E5, dark count rate of 7 MHz, crosstalk of 7%, dynamic range of 85,000 pixels, overall recovery time of 32 ns at room temperature and over-voltage of 3.5 V. The improved PDE at peak wavelength of 420 nm was 30%.