Study On Extraction Technology Of SRAM SEU Effect Parameters Based On SOI CMOS

This paper is supported by "SOI MOS devices anti-radiation project(No.6131720303)" of973Fund. With the development of space technology and nucleartechnology, more and more attentions are paid on the performance and reliability ofintegrated circuits under the irradiation environment. Especially in the outer space andnuclear irradiation environment, single event effects will cause the circuit state changes,and may even damage the entire circuit. With the development of the technology ofintegrated circuit, the size of the device is getting smaller and smaller. The feature sizeof VLSI has reached12nm, which makes the impact of single event effects of the circuitincreasingly serious. As a result of full dielectric isolation, SOI devices eliminate thelatch-up and play a good role in the anti-irradiation technology. Experimentalinvestigation of simulation analysis of single event upset effect of6T SRAM based onSOI CMOS devices will be conducted in this paper.SRAM is the storage unit that is sensitive to single event upset effect in theaerospace electronic systems.6T SRAM is the bi-stable circuit which comprises twoinverters. There are a lot of cosmic rays in the universe and outer space, which willcause single event effects in the integrated circuits. In order to obtain key parameters ofSEU effects of6T SRAM quickly and easily, this paper studies the extractiontechnology of SRAM SEU effect with EDA tools. With the ISE-TCAD simulationsoftware, the two-dimensional single-particle simulation of single SOI NMOS device issimulated, and the influence of single event LET value, the drain voltage, the incidentposition and angle of incidence on the transient pulse current is studied. So theworst-case of transient pulse current induced by single event is also obtained. Weibullfunction is the most widely used research model in reliability field. the exsit of shapeparameter makes the Weibull function model is very flexible in the curve fitting. Usingthe Matlab software to fit the original pulse current data into the Weibull function, andso the three characteristic parameter of Weibull function is obtained. The transient pulsecurrent is described as piecewise linear model which is added to Hspice simulationnetlist, and the key parameters such as upset threshold and critical charge is obtained bycircuit simulation method. The contrast of the piecewise linear model simulation andWeibull distribution model simulation is also done, and the result is almost identical.For the devices and integrated circuits are exposed in total doses irradiationenvironment, the properties of anti single event effect of SOI MOS devices may be deteriorate. Therefore the influence of different total doses irradiation of the6T SRAMSEU effects is also studied, and is compared to the result of the single event simulation.It is found that under the total dose ionizing radiation environment, the anti SEU effectsof SOI MOS devices has deteriorated. Finally the single event upset effects of ROCKSRAM is simulated, which result is compared to the6T SRAM unit.