The Key Technology Of Diamond Film Radiation Detector

In recent years,nuclear radiation technology has been widely used in various industries and fields,bringing huge social and economic value to our development.But at the same time,nuclear radiation also brings potential risks to humans and the natural environment.In order to make better use of radiation while avoiding its risks,research on radiation detection is very important.Due to the superior performance of diamond material,the detector made based on it has the characteristics of radiation resistance,high temperature resistance and fast response compared with other semiconductor detectors.In addition,the continuous development of synthetic diamond technology makes it play a role in the field of radiation detection Plays an increasingly important role.This article focuses on the research of CVD diamond thin film radiation detectors.First,it studies the advantages of making detectors made of diamond materials.Due to many excellent properties,it has become the first choice for radiation detectors in the new era.Then several preparation methods of CVD diamond film were introduced,and the MPCVD method was used to prepare the diamond film,which was used for the production of the radiation detector probe later.The diamond samples were characterized by Raman scattering and AFM respectively,and the content and surface of the diamond phase of the samples The morphology was analyzed.The Cypher-ES instrument was used to study the microscopic characterization of diamond ultraviolet radiation response,and the dark current density of diamond samples was tested.The dark current density of single crystal diamond and polycrystalline diamond under unit electric field was 8.75[p A/mm²]/[V/?m]and 24.3[p A/mm²]/[V/?m],the linearity is good in the test electric field;the photocurrent response of the diamond surface is also tested,and the output current changes are observed by changing the UV radiation voltage(0-2.25V),As the radiation voltage increases,the output photocurrent also increases significantly.The analysis shows that the diamond film has a good radiation response.Finally,the designed CVD diamond film radiation detector is used to test gamma rays.First,a low-cost heavily doped boron silicon wafer(100)is used as a substrate,and a CVD diamond film grown on the silicon wafer is used as a radiation sensitive layer.Then analyzed the advantages and disadvantages of several different electrode structures and the scope of application.Finally,a sandwich electrode structure is selected,100nm Au is sputtered on the surface of the sample,and then the circuit board is designed to package the probe.Finally,the detector is tested with a ⁶⁰Co steady-state radiation source,that is,?-ray irradiation with a dose rate of 9.6Gy/h and an energy of 1.25Me V.As the cobalt source is lifted out of the well,the output voltage has an instantaneous rising pulse,and the response rate of change 11.2%.It proves the feasibility of the structure designed in this paper as a gamma radiation detector.