Fabrication of pn junction CdTe radiation detectors by thermal diffusion doping with electron beam

CdTe is used as a compound semiconductor detector that operates at room temperature. Because CdTe has a thick crystal of approximately 1mm, it is necessary to apply a high voltage to extract the charge generated by incident x-rays. Although it is necessary to suppress the leakage current that increases when a high voltage is applied, this leakage current can be suppressed by using the rectification effect of the diode. A pn junction is used as the diode, which has a potential barrier formed inside the crystal and is considered to have high heat resistance and mechanical resistance. Therefore, we propose a doping method using thermal diffusion using an electron beam. In order to verify thermal diffusion doping using an electron beam, we fabricated a pn-type CdTe radiation detector using an EBAS (Electron Beam Assist Source) device, which is an electron beam annealing device.