Study Of The Wide-base Silicon Diode(PIN) Detector

With the development of nuclear science and technology, nuclear facilities, radiation equipment are widely applied to military, medical industries, agriculture, geological surveys, scientific research and teaching areas. Accordingly, the public suffered higher risks from nuclear weapon accident, nuclear reactor accident, radiation equipment, radioactive waste storage and transportation accidents, medical radiation accidents. The public security puts forward higher requirements to radiation detection technology. In this paper, the PIN diode neutron detector is used to measure the cumulative dose of fast neutron radiation equipment. It has a lot of advantages such as small size, simple measuring method, and good linear does response when the dose is high.The paper firstly introduces theγ-ray and fast neutron interaction with silicon materials. It particularly introduces displacement damage-defect group produced by the fast neurton irradiated silicon material and explains the space charge model of the defect group. The fast neutron irradiation silicon crystals produced radiation damage-defect groups. The most important influence of radiation damage to semiconductor material is the removal effects of carrier and minority carrier lifetime reduction. According to the above two influences, the author builds the model which measures the relationship the PIN diode detector voltage change with the radiation dose.Based on the model, the author analyzes PIN diode detector voltage variation effects with different minority carriers lifetime,different base width, different current densities and different initial resistivity. And then according to the sensitivity formula, we can get the influence of the above mentioned parameters on the sensitivity of PIN diode detect fast neutron.Then, making use of the simulation software Tsuprem 4, the author simulates the PIN diode manufacturing process, and analyzes the main process.Making use of the device simulation software Medici, the response characteristics of PIN diode with fast neutron irradiation were studied. First of all , the change of base electric field and electric potential under different doses and the change of PIN diode voltage variation with the fast neutron irradiation dose are discussed and analyzed. Then the stability of PIN diodes detector and the temperature effects of PIN diodes are discussed and simulated. Finally, the performance and leakage current of PIN diode radiation detector were simulated. The relationship between the sensitivity of PIN diode detector and the applied constant current was simulated. The relationship between the sensitivity of PIN diodes detector and base width was also studied.The reason and factor effecting were anaiyzed.this paper introduced two other methods to reduce the detector leakagecurrent.The leakage current of PIN diode wih guardring was studied.Finally, the model calculation result and device simulation results are compared to verify the consistency between model under the radiation dose (0-150Gy) and simulation result. In this paper, the theory and simulation study of PIN diode detector provides some practical significance and reference value to PIN diode detector with high sensitivity.