Research On Developing An Improved Method Of PMOS Dosimeter And A New Kind Of Dosimeter Based On Floating Gate Transistor

With the rapid development of modern space technology,all kinds of electronic components in the spacecraft electronic system suffer from the space radiation environment,which makes the performance of the components worse or even damaged,and threatens the normal operation of the spacecraft seriously.Therefore,it is very important to develop anti-radiation reinforcement technology to improve the anti-radiation performance of electronic components in spacecraft,and the collection of space radiation environmental data is the basis for the study of anti-radiation reinforcement technology,the collection and research of Space Radiation Environment data is of great significance to improve the reliability and operational reliability of spacecraft.For a long time,all countries have invested a lot of energy in the research of space radiation environment detection technology,and PMOS dosimeters are widely used in the detection of space radiation environment in various countries because of their small size,light weight,low power consumption,simple and real-time measurement.However,with the increasing applications of PMOS dosimeters,the requirements for the performance of PMOS dosimeters have gradually increased,and some problems existing in traditional PMOS dosimeters have gradually come to light,such as the low sensitivity of PMOS dosimeters in low dose rate environment,the probe structure of PMOS dosimeter is subject to temperature,dose rate and annealing,which leads to the problem of measurement accuracy.Therefore,it is of great practical significance to improve the performance of traditional PMOS dosimeters and actively develop new dosimeters with better performance.Based on the above problems,this paper has carried out the following work and achieved certain results:In this paper,the probes commonly used in PMOS dosimeters in China have been selected to carry out cobalt source irradiation experiments under different working circuits and obtain the change of threshold voltage of sensitive parameters,thus,the radiation response of the probe under different working conditions is analyzed and compared,and its working principle is analyzed.The experimental results show that the sensitivity of the constant current injection circuit commonly used in PMOS dosimeters in China is the lowest,while the sensitivity of the radiation response of the 5V bias mode is greatly increased,but the linearity of the radiation response is not enough,the sensitivity of the probe radiation response can be greatly improved by using the differential operating mode,which is more than 4 times that of the constant current operating mode,the performance of PMOS dosimeter is improved.In addition,a new type of dosimeter FGDOS based on floating gate transistor as probe has been preliminarily explored and studied.In this paper,the cobalt source irradiation experiments are carried out on floating gate transistors in the two states of erasure and programming,and the curves of the sensitive parameter threshold voltage and the total dose are obtained.According to the test results,it is pointed out that the floating gate transistor can be used as the dosimeter probe in the programmed state,and the working route that the floating gate transistor can be used as the radiation probe is given,that is,after receiving the dose and the drift of the threshold voltage of the probe reached a certain value,the probe was recharged and the total dose received could be added up to the previous cumulative dose.In this paper,a verification test is carried out on the proposed working route,and a suitable measuring point for reprogramming the floating gate probe is selected.The reliability of floating gate transistor as dosimeter probe is also discussed in this paper.Through experiments,it is found that the threshold voltage of the floating gate transistor in the programming state is susceptible to temperature,and the high temperature environment has a greater influence on the threshold voltage of the device,which will have a greater impact on the reliability of the floating gate probe.Through the dose rate test,it is found that the floating gate transistor does not have a low dose rate radiation sensitivity enhancement effect.This paper also makes a preliminary exploration of the radiation response of the floating gate transistor probe under different energy electron rays.The experiment found that the threshold voltage of the sensitive parameter of the floating gate transistor used in the experiment basically did not drift under 1.1Me V electron beam irradiation.The appearance of this result may affect the reliability of the floating gate dosimeter probe.The improvement method proposed in this paper to the differential working circuit of the traditional PMOS dosimeter greatly improves the sensitivity and performance of the constant current injection working circuit dosimeter commonly used in my country.Therefore,this paper provides a preliminary theoretical basis and feasible working route for using floating gate transistor as dosimeter probe,and provides a certain basis for the systematic development of FGDOS.