Study Of The SiC Semiconductor Material And Pixel Detector

In recent years,SiC material has been proved to be used in space exploration,nuclear power plants,nuclear reactors and other high-radiation,high-temperature extreme environment,so the SiC radiation detector in the high-temperature,radiation-resistant aspects.A great deal of meticulous work has been done in the field of particle detection with different energies.The results show that the SiC detector has the advantages of fast time response,good temperature stability and strong radiation resistance in?-particles,?-rays,neutrons and X-rays.Pixel detectors have the characteristics of high spatial resolution,low noise and radiation imaging.Compared with traditional unit detectors,pixel detectors also have good tolerance to local defects,and have gradually become a research hotspot in the field of space detection.In this paper,4H-SiC Schottky pixel detector was designed and fabricated.The electrical properties and detection performance of?-particles were studied.The neutron detection and detector anti-irradiation characteristics based on4H-SiC detector were also studied.Firstly,the surface morphology and crystal structure of the samples were analyzed by atomic force microscopy and Raman spectroscopy using chemical vapor deposition of homoepitaxial SiC films.The results show that the surface morphology of different samples is basically the same,showing good uniformity and surface roughness up to 3.91 nm.Raman spectroscopy shows that SiC film has a single crystal form and good crystal quality,which meets the requirements of preparing pixel detectors.According to the metal semiconductor contact theory,the process mature condition and the thermal stability of the Schottky diode,the electrode materials required for forming the ohmic contact and the Schottky contact are determined,wherein the ohmic contact electrode material is Al,Ti and Au,The Schottky contact material is Ni and Au.Based on this,a SiC pixel detector device was fabricated.Then,the electrical performance of each pixel of the pixel detector is tested and analyzed.The barrier height and ideal factor of each pixel are calculated by the forward I-V curve,and the consistency and difference of each pixel are discussed.The inverse I-V and C-V curve are obtained.Parameters such as leakage current and junction capacitance of each pixel of the pixel detector.The performance of each pixel of the 4H-SiC Schottky pixel detector was tested using radiation sources with energies of 5.15 MeV(²³⁹Pu)and5.48 MeV(²⁴¹Am),respectively.The signal amplitude and the energy spectrum of the alpha particle response of each pixel detector test system under zero bias voltage conditions are studied.The energy spectrum variation law of each particle's alpha particle radiation source under different bias voltages is studied.Under low voltage conditions,the low energy tailing phenomenon disappears with the increase of bias voltage,and the full depletion of each pixel is determined.The energy resolution of each pixel with voltage and full depletion.Finally,the ⁶LiF/4H-SiC is used to evaluate the white light neutron source.The results show that the 4H-SiC detector exhibits good particle detection and anti-irradiation performance for white light neutron source.At the same time,SiC radiation detection has strong anti-irradiation characteristics for long-term,high-dose gamma rays.After the detector was subjected to continuous irradiation for 94.3 hours and the total dose was 1000kGy?-ray irradiation experiment,the?-particle response energy spectrum,?-particle resolution and the omnipotent peak area of the two energies were not compared before irradiation.There have been significant changes.