Design and analysis of novel high-performance thick epitaxial SiC radiation detector with low operating voltage by multiple p-type buried layers

Abstract

In this work, epitaxial silicon carbide (SiC) radiation detectors (E-SRD) were modeled, and SiC PiN diodes with multiple p-type buried layers (PBL), named MPBL PiN, were proposed as E-SRD to address the problem that detection performance of E-SRD using convention PiN diodes (Cov. PiN) with thick epilayer is limited by its high fully depleted voltage (VFD). The charge collection efficiency (CCE), pulse height and relevant physical mechanism affecting detection performance of E-SRD were investigated. When both Cov. PiN and MPBL PiN have a 100 μm epilayer with n-type doping concentration of 3 × 1014 cm−3, the VFD of Cov. PiN reaches 2800 V, while that for MPBL PiN is only 550 V. 14 MeV neutron detection simulation results showed that, compared to Cov. PiN, the CCE, pulse height and radiation resistance of MPBL PiN improve significantly under low operating voltage within 1000 V, meanwhile its lower near-surface electric field is conducive to reducing leakage. Further, since the VFD of MPBL PiN is proportional to the thickness of the epilayer (HE) instead of to the square of the HE like Cov. PiN, the VFD of MPBL PiN with ultra-thick epilayer is much lower than that of Cov. PiN. Therefore, under commonly used operating voltage within 1000V, the sensitivity and pulse height of MPBL PiN can be proportional to the HE, while that of Cov. PiN hardly improved when HE is above 100 μm. So MPBL PiN can give full play to the high-performance detection advantages of ultra-thick epilayer, which is expected to promote the development and application of ultra-thick epilayer E-SRD with low operating voltage.