Research On Two-dimensional Silicon Detector With Small Capacitance

X-ray pulsar navigation is an important strategic development direction for spacecraft to achieve high-precision autonomous navigation,which belongs to the hot research field of aerospace science and technology.Silicon detectors are mainly used to detect and collect the energy information of X-ray radiated by pulsars,and provide full-information,full-airspace,long-term,high-precision,and autonomous navigation information for spacecraft performing space exploration missions.Independent research and development of high-end new silicon detector chips belonging to my country is the only way to break the western monopoly and realize the rise of great powers.Therefore,this article mainly studies the two-dimensional silicon detectors with small capacitance for X-ray pulsar navigation.The specific contents are as follows:1.The structure design,electrical simulation and chip fabrication of 314 mm~2double-sided spiral silicon drift detector are studied.Firstly,the mathematical variational method is used to calculate the potential and electric field distribution of the spiral silicon drift detector with the best carrier drift path.The structural design parameters such as the pitch and width of the spiral rings are determined,and a 314mm~2double-sided spiral silicon drift detector is designed.Secondly,the distribution of potential,electric field and electron concentration are simulated to confirm that there is an optimal electron drift channel in the detector.The single event transient effect is also simulated,and the anti-radiation reinforcement of the detector’s collecting anode is proposed.Then,the detector chip is fabricated and the leakage current and capacitance are tested.The leakage current is about 34 p A and the capacitance is about 7 p F,which indicates that the detector has excellent performance.Finally,a large-area silicon drift detector array with hexagonal arrangement is designed.The application of magnetic field,new refrigeration and optimization design are used to solve the possible problems of difficult collection of signal electrons,high fever and poor physical structure carrying capacity in the silicon drift detector array.2.The structure design and electrical characteristics of the full-floating pixel detector are studied.Silicon drift detector does not have position resolution capability.In order to meet the position resolution requirements of deep space detection,a full-floating pixel detector with small capacitance is designed.Firstly,inspired by the design idea of silicon drift detector,a full-floating pixel detector is designed.The floating electrode is used to reduce the area of the collection electrode of the detector,which solves the shortcomings of the traditional pixel detector,such as large area of the collection electrode,large leakage current and capacitance,and high noise,thereby improving the position and energy resolution of the pixel detector.Secondly,the influence of detector thickness and floating electrode spacing on detector performance is analyzed,and it is determined that when the thickness is 300μm and the floating electrode spacing is 5μm,the performance of the detector is the best.Finally,the distribution of potential,electric field and electron concentration of the detector array is simulated.The results show that the potential distribution is uniform and there is no dead zone,which proves that the structure design of the fully suspended pixel detector is reasonable.