Research On Radiation Effects Ground-based Testing Technology

The radiation effect induced by the high energy ion in radiation environment striking at semiconductor material is one of the main reliability challenges in spacecraft electric system. With the advancing of integrate circuit technology, the limitation of computer aided simulation becomes apparent, while the importance of radiation effects ground-based testing is ever increasing in the process of research on radiation effect mechanism and integrate circuit hardening by design.Nowadays the method of evaluating the failure modes and the environment factor in the radiation testing is not systematism. In this thesis, we aim at the main radiation effects of current CMOS VLSI, and study the test platform and environment factor in the radiation testing. The main works and contributions of the thesis are as follows1) We develop a versatile test platform for radiation effects. Based on the analysis of single event latchup, single event upset, single event transient and total ionizing dose, the evaluating method is presented, the parameters for radiation effects characterization are selected,and the platform is designed. Mainly consisted of current monitor system and data system, the test platform can evaluate the four effects mentioned above. The modularization design style makes it can be easily transplanted.2) We study the environment factors and their effects on test results. By mechanism analysis and device simulation method, we study the temperature and bias dependence of single event latchup and single event upset. The results show that the threshold LET of single event latchup decrease with elevated temperature, and the threshold LET of single event upset increase when the bias is low. Also we study the effects of distance between radiation resource and the device under test and the angle of incidence on test.3) We develop a measurement system for radiation effect on DSP. The system can obtain the internal SRAM upset section accurately and detect the current real-time. The temperature measurement and control module, and voltage adjustable module in the system can evaluate the circuit radiation effects under worst-case.4) Utilizing 60Coγray, pulsed laser and heavy ion accelerator, we complete the total ionizing dose and single event effects testing of IO, SRAM, DFF chip and a certain DSP. The effectivity and reliability of the test method and test system are proved. The methods of radiation source selection and experimental data analysis are also acquired.