基于4H-SiC肖特基二极管的中子探测器

Neutron Detector Based on 4H-SiC Schottky Diode

针对当前极端环境下耐辐照半导体中子探测器的需求,采用耐高温、耐辐照的碳化硅宽禁带半导体材料,利用6 Li(n,α)3 H核反应原理,研制了基于4H-SiC肖特基二极管的中子探测器。利用磁控溅射完成中子转化层的制作,并用SEM表征6 LiF膜厚。在10～600V反向偏压下,漏电流维持在6.4nA以下,表明探测器具备良好的半导体-金属肖特基整流接触。利用241 Am源研究探测器对5.486 MeV的α粒子的响应,测得分辨率为4.5%。同时,利用该探测器测量了由临界装置产生并经石蜡块慢化后的热中子,观测到热中子与6 Li作用产生的α和T粒子信号的实验结果。

A neutron detector exploiting the 6Li（n,a）3H reaction was fabricated by using semiconductor epitaxial 4H-SiC as the detection medium. This work aimed to develop neutron detector with increased resistance to radiation effects, thus it can be used in harsh environments. The 6LiF neutron converter layer was deposited by magnetron sputtering method and was characterized by scanning electron microscope （SEM）. While the reverse voltages of the studied diode were tested from 10 V up to 600 V, the reverse current was below 6.4 nA, indicating a successful formation of Schottky contact between epitaxial 4H-SiC and Ni. The resolution factor for 5. 486 MeValpha particles was acquired as 4.5% by means of a 241Am source to this purpose. Response signals of neutron detector based on 4H-SiC Schottky diode to thermal neutron generated by critical assembly and slowed down by paraffin wax were obtained.