Correlation between the surface roughness and the leakage current of an SSB radiation detector

Leakage current is one of the main noise sources of in radiation detectors, especially in a semiconductor radiation detector used for energy spectroscopy. A Silicon Surface Barrier (SSB) radiation detector was constructed to study the correlation between its surface roughness and leakage current. The surface roughness was analyzed with an Atomic Force Microscopy (AFM). All the constructed SSB radiation detectors in this study were processed in same way, but the etching solutions used to roughen the silicon surface were different. The correlation coefficient between the surface roughness and the leakage current was 0.848. This value indicates that the surface roughness and the leakage current have a relatively strong relationship, and a proper etching condition can minimize the leakage current in a semiconductor radiation detector based on silicon. The energy spectrum for an alpha particle from 238Pu was also measured with the constructed SSB radiation detector.