Study On The Process Of Silicon Microstructure Semiconductor Neutron Detectors

The detection of neutron has a special place in the particle detection technology.It plays an important role in particle physics,nuclear physics,medical physics,astrophysics,archaeology,geology exploration and other fields,which promoting the rapid development of the neutron detector.The ~3He-based proportional counters are widely used in environmental security,neutron radiation protection,food testing,health and epidemic prevention.~3He gas resource has become a problem to be solved with the increase of demand.The silicon microstructured semiconductor neutron detectors solve the problem of self-absorption existed in planar semiconductor neutron detector,and their low power requirement,high energy resolution,quick responsetime,relieve the contradiction with supply of ~3He proportional counters.In order to improve the performance of the silicon microstructured semiconductor neutron detectors and the promotion of commercial,the technology process of silicon semiconductor microstructured neutron detectors is studied in this paper.The porous silicon microstructured semiconductor neutron detectors were fabricated.In order to reduce the leakage current,the key fabrication processeshave been optimized.It is found that the change of the leakage current is smaller using Al etchant to open Al window.The leakage current is improved after deep silicon etching using the optimized parameters.After wet etching of TMAH,the leakage current reduced obviously.And from the neutron irradiation test,we cansee that the silicon microstructured semiconductor neutron detectorscan surely increase the thermalneutrondetection efficiency.The result of porous silicon microstructured semiconductor neutron detectors'big leakage current is analyzed,and has been improved from three aspects.The silicon microstructure withbetter vertical and smoother wall can be obtained using wet etching.The detectors using diffusion can have smaller leakage current and better detection performance than passivation.And the adding of guard ring can also reduce the leakage current to some degree.By studying the above problems,we design a new fabrication process of silicon semiconductor microstructured neutron detector and provide an important basis for the fabrication of the silicon microstructured semiconductor neutron detectors.