Research Of The Analog Circuit Performance Under Combined Stress

The reliability of MOS device can affect the performance of the device, which also can affect the performance of the circuit, so that the further development of the integrated circuit is restricted. The reliability problems of deep submicron CMOS devices include NBTI(Negative Bias Temperature Instability) effect, CHC(Channel Carrier Injection), TID(Total Ionizing Dose) effect, etc.. With the further development of the integrated circuit, these effects will be further increased. Research on these problems has become more and more common, but the research on the integrated effects of the use of aerospace equipment is still relatively few. At present, as human explores the space more and more, the demand for space radiation tolerance circuit is also increasing, so it is necessary to study the reliability of the circuit combined with the total radiation dose effect.Based on the CMOS 65 nm process, the influence of the combined effects on the threshold voltage and the circuit performance of the device are studied in this paper. We introduce the short-term model of device level and the long-term model of circuit level at first, and then introduce the TID and CHC comprehensive effects model obtained by experiment. According to the circuit level long-term reliability model of CHC, the MATLAB numerical analysis method of the model is obtained in order to obtain the more accurate threshold voltage degradation. On this basis of this, the reliability analysis process of AMS(Analog and Mixed Signal)circuit is established, and the method of joint iterative analysis of MATLAB and SPICE is established. The degradation of circuit parameters is reduced to a certain step by step iteration to the reliability model, which reduces the error of the reliability prediction of the differential amplifier. Compared with 10% of the time before and after the iterative threshold voltage degradation, the iterative algorithm is more than 4.7 years after the iteration of the algorithm. Finally, the offset voltage of the amplifier is obtained by the circuit mismatch simulation. The circuit life is estimated to be about 3.2 years. The data is supported by Sy RA(System Reliability Analyzer), which indicates that the iterative analysis method established in this paper is correct.On the basis of the circuit level long-term reliability model, this paper uses MATLAB and SPICE combined iterative analysis method to analyze the degradation of VCO(Voltage Controlled Oscillator). At the same time, the results of simple superposition of CHC and TID effects are compared with the results of their combined model, which shows that the latter has a higher threshold voltage degradation, which indicates that CHC and TID can interact and make VCO degradation more serious. Finally, according to the analysis of the comprehensive effect of the degradation of VCO performance, the output frequency of 10 years decreased by 33.2%, far beyond the limit of the degradation of the frequency of its life, to make the circuit used in the life of more than 10 years of space equipment, also need to be radiation hardened and structure impoved, the analysis of radiation hardening and comprehensive effect reliability prediction provides a certain reference.