Home         Authors   Papers   Year of conference   Themes   Organizations        To MES conference

Two-Parameter Model for Estimation SEE Sensitivity of VLSI under Ion Irradiation
Authors
	Chumakov A.I.
Date of publication
	2016
Abstract
	Two-parameter model for estimation SEE sensitivity of VLSI under ion irradiation is discussed. An approach to IC SEE sensitivity parameters estimation based on charge collection by a point node is considered. The improved model takes into account finite sizes of sensitive volume and allows estimation of an angle dependence of threshold LET more correct. The standard approach for estimation of single event effect (SEE) sensitivity is assumed that the area of charge collection from the charged particle track is fixed, while sensitivity of IC elements has a spread reflecting experimental dependency of SEE cross section change on linear energy transfer (LET). It is clear, that it is the vice versa in a practice. The sensitive volume may vary, but the critical charge is constant for the same type of VLSI elements. The point node model of charge collection allows to overcome this contradiction. The value of collection charge (ionizing response) decreases according exponential function versus the distance between points of sensitive node and charge generation. In case of incidence of ion particle at a distance from the center of the point sensitive area, LET needed for SEE is determined by integrating along of the track length. Two parameters need to describe the dependence of SEE cross section as a function of LET: the effective collection length (lc) and the threshold LET (Lzo). Unfortunately, this model gives more small changes in threshold LET dependencies on an angle of incidence than the experimental results. The effect of finite sizes of the sensitive area allows to overcome this obstacle. SEE cross section at the corresponding value of LET increases. One can see a satisfactory correlation between experimental results and simulation results for different SEEs: SEUs, SEFIs, SELs and SETs for various VLSI, but the extra parameter, namely radius of sensitive area (rs) is added. Moreover, the effective collection length lc is correlated with design rules, thus the diffusion processes of charge collection predominate on drift processes. The analysis showed that an acceptable accuracy can be obtained within the two-parameter model if it is assumed that rs=lc. We can observe change of threshold LET dependence on the angle of incidence practically as 1/cos until 60o. In this case it is not always possible to obtain satisfactory agreement with experimental data in subthreshold area. However, the error in this area does not lead to noticeable errors in the estimates of the SEE rate under the cosmic ion irradiation.
Keywords
	ion irradiation, single event effects (SEE), SEE cross section, VLSI
Library reference
	Chumakov A.I. Two-Parameter Model for Estimation SEE Sensitivity of VLSI under Ion Irradiation // Problems of Perspective Micro- and Nanoelectronic Systems Development - 2016. Proceedings / edited by A. Stempkovsky, Moscow, IPPM RAS, 2016. Part 4. P. 139-144.
URL of paper
	http://www.mes-conference.ru/data/year2016/pdf/D021.pdf