一种快速推算栅极氧化膜TDDB寿命的方法

提出了一种快速推算栅极氧化膜TDDB寿命的新方法.该方法可以用于对工艺的实时监控.通常情况下,为了得到栅极氧化膜在器件使用温度下的TDDB寿命,必须得到三个在一定温度下的不同电压下的TDDB寿命.然后使用一定模型(E模型或者1/E模型)和这个三个寿命推算出氧化膜在器件使用温度下的寿命.比较常用的是E模型.但是为了保证使用E模型推得的寿命的准确性,必须尽量使用较低电压下的寿命来推算想要的寿命.显然,为了获得低电压下的TDDB寿命,必须花费相当长的测试时间(甚至1个月).这对于工艺的实时监控来说,是不能接受的.文中提出一种新的推算栅氧化膜TDDB寿命的方法.运用该方法,可以快速、准确获得栅氧化膜的TDDB寿命,而花费的测试时间不到普通方法的1/1000000.在该方法中,巧妙地同时利用了1/E模型和E模型.

One Method for Fast Gate Oxide TDDB Lifetime Prediction

A method for fast gate oxide TDDB lifetime prediction for process control monitors (PCM) is proposed.For normal TDDB lifetime prediction at operation voltage and temperature, we must getthree lifetimes at relative low stress voltages and operation temperature. Then we use these three lifetimes to project the TDDB lifetime at operation voltage and temperature via the E-model. This requires a very long time for measurement. With our new method,it can be calculated quickly by projecting the TDDB lifetime at operation voltage and temperature with measurement data at relatively high stress voltages. Our test case indicates that this method is very effective. And the result with our new method is very close to that with the normal TDDB lifetime prediction method. But the measurement time is less than 50s for one sample, less than 1/100000 of that with the normal prediction method. With this new method,we can monitor gate oxide TDDB lifetime on-line.