The track structure of high-energy heavy ions was calculated in thispaper and using Monte Carlo method, effects of the track structure onsingle event upset was studied. Taking into account the track structure,devices with small sensitive cell and low upset threshold show lowerupset cross sections and upset rates, when compared with LETcalculation. When ion becomes heavier, this decrease is remarkable evenfor devices with moderate dimension sensitive cell and higher upsetthreshold. In general, ion track shows effect when effective depositedenergy is comparable with upset threshold. High-energy heavy ions canpenetrate into thick material, in addition large dimensional track haschance to deposit enough energy in neighboring cells simultaneously.Both of these two cases can give rise to multiple-bit upsets. And thismultiple-bit upsets effect can't be calculated with LET.%利用解析法计算了高能重离子的径迹结构,通过Monte Carlo方法研究了径迹结构对微电子芯片单粒子翻转的影响.结果表明,考虑了径迹结构的影响后,当离子能量较高时,具有小尺寸灵敏单元、低翻转阈值的芯片的翻转截面较传统的LET描述结果小许多;当离子更重时,这种差别对灵敏单元尺寸较大、翻转阈值较高的芯片也变得较明显.即离子径迹结构的影响是通过其有效地沉积到灵敏单元中的能量与翻转阈值相比较而表现出来的.还研究了作用距离较深、结构宽大的径迹造成的相邻多个灵敏单元的同时翻转,即多位翻转现象,这是用LET 所不能反映的.
展开▼
