利用FN电流估计薄栅MOS结构栅氧化层的 势垒转变区的宽度

通过数值求解整个势垒的薛定谔方程，发现FN电流公式中的B因子强烈依赖势垒的转变区的宽度，而C因子则弱依赖于势垒的转变区的宽度．给出了一种利用WKB近似所得的处理电子隧穿存在转变区势垒的过程，并得到一个FN电流的分析表达式．它可用来估计薄栅MOS结构的栅氧化层的势垒转变区的宽度．在转变区的宽度小于1nm时，它与数值求解薛定谔方程的结果吻合得很好，表明该方法可以用来估计势垒转变区的宽度．实验的结果表明B因子随温度有较大的变化，这个结果验证了该方法的部分预测结果．

Estimate of Width of Transition Region of Barrier for Thin Film Insulator MOS Structure Using Fowler-Nordheim Tunneling Current

According to the numerical solution to the Schro¨dingerequation,factor B is observed to depend strongly on the width of transition region of barrier,while factor C is almost independent of the width.An analytic expression about FN tunneling current has been obtained using the WKB approximation,as well as the barrier that includes a transition region,which can be applied to estimate the width of barrier transition region for the gate oxides of thin MOS structures.The result obtained being compared with that from the numerical solution to Schro¨dinger equation,it is found that they agree with each other very well when the width of barrier transition rigion is less than 1nm.It indicates this method may be used to estimate the width of barrier transition region.The experimental result also shows that B factor changes greatly with the temperature,which can partly prove the method.