基于半绝缘GaN自支撑衬底的肖特基型α粒子探测器的制备及性能分析

Preparation and performance analysis of Schottkyαparticle detector based on semi-insulated GaN self-supporting substrate

本实验以半绝缘GaN自支撑衬底作为核辐射探测器主体,采用简单的三明治结构,通过在其正面(Ga面)沉积Ni/Au作为肖特基接触金属电极,反面(N面)沉积Ti/Al/Ti/TiN作为欧姆接触金属电极,成功制备了一种肖特基型α粒子探测器。所制备探测器在室温下拥有较小的结电容和极低的漏电流,经过快速退火后,探测器在反向偏压200 V时的漏电流仅为0.19 nA。为探究光照对探测器的影响,又在光照和避光条件下分别对探测器进行了I-t测试,发现其对光的响应也十分敏感。最后,对肖特基型探测器在不同反偏电压下进行α粒子的能谱测试,发现在反向偏压为200 V时,探测器可达到最佳能量分辨率32.82%。

In this experiment,a kind of Schottkyαparticle detector was successfully prepared by depositing Ni/Au as the Schottky con-tact metal electrode on the front(Ga face)and Ti/Al/Ti/TiN as the ohmic contact metal electrode on the back(N face)on the semi-insulated GaN self-supporting substrate as the main body of the nuclear radiation detector.The detector has small junction capacitance and very low leakage current at room temperature.After rapid annealing,the leakage current of the detector at 200 V reverse bias is only 0.19 nA.In order to explore the influence of light on the detector,I-t test was carried out on the detector under the condition of light and light avoidance,and it was found that its response to light was also very sensitive.Finally,the energy spectrum of the Schottky detector under different reverse bias voltage is tested.It is found that the optimal energy resolution of the detector is 32.82%when the reverse bias voltage is 200 V.