The merits and limitations of local impact ionization theory [APDs]
The merits and limitations of local impact ionization theory [APDs]
复制标题
局域碰撞电离理论 [APDs] 的优点和局限性
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
D. Ong
中科院分区：
文献类型：
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作者：
S. Plimmer;J. David;D. Ong
本文利用GaAsp/sup +/-i-n/sup +/s（i区厚度w在1 /spl μ/m和0.025 /spl μ/m之间）的倍增测量和雪崩过程的蒙特卡罗（MC）计算研究了局域电离理论的适用性。乘法的局部表达式能够在p/sup +/-i-n/sup +/s中令人惊讶地很好地预测测量值，其中i区厚度w薄至0.2 /spl μ/m，在死区效应之前，载流子没有足够的能量来消除死区，导致显著的误差。此外，只有一个非常简单的修正本地的表达式是需要准确地预测乘法场迅速变化的突变单侧p/sup +/-n结掺杂高达10/sup 18/ cm/sup-3/。然而，MC建模还表明，复杂的死腔效应导致局部电离系数越来越不代表器件中的位置相关值，因为w降低到1 /spl mu/m以下。因此，局部模型在预测乘法中的成功归因于已经包含在局部系数的实验确定的值内的死空间信息。有人建议，这些因此应该被认为是有效的系数，尽管存在死腔效应，仍然可以使用现有的本地理论有效地量化倍增和击穿电压。
Multiplication measurements on GaAs p/sup +/-i-n/sup +/s with i-region thicknesses, w, between 1 /spl mu/m and 0.025 /spl mu/m and Monte Carlo (MC) calculations of the avalanche process are used to investigate the applicability of the local ionization theory. The local expressions for multiplication are able to predict the measured values surprisingly well in p/sup +/-i-n/sup +/s with i-region thicknesses, w, as thin as 0.2 /spl mu/m before the effect of dead-space, where carriers have insufficient energy to ionize, causes significant errors. Moreover, only a very simple correction to the local expressions is needed to predict the multiplication accurately where the field varies rapidly in abrupt one-sided p/sup +/-n junctions doped up to 10/sup 18/ cm/sup -3/. However, MC modeling also shows that complex dead-space effects cause the local ionization coefficients to be increasingly unrepresentative of the position dependent values in the device as w is reduced below 1 /spl mu/m. The success of the local model in predicting multiplication is therefore attributed to the dead-space information already being contained within the experimentally determined values of local coefficients. It is suggested that these should therefore be thought of as effective coefficients which, despite the presence of dead-space effects, can be still be used with the existing local theory for efficiently quantifying multiplication and breakdown voltages.