帶對帶穿透效應之分析與測量及其在P型快閃記憶元件的設計

Abstract

首先，我們利用在不同的溫度下來量測金氧半場效電晶體元件關閉狀態的電流，以便確認它的機制。然後我們再對這個帶對帶穿透模型作分析，因為過去的一維帶對帶穿透模型並沒有考慮到洩極濃度與橫向電場的影響，經過模擬閘極引發汲極漏電流與量測結果的比較後，發現並不相符合。因此，我們提出了一個完整的二維模型，除了考慮縱向電場之外，同時也考慮了橫向電場對帶對帶穿透效應的影響，而且本模型也將溫度的效應考慮進去，使本模型也可以在不同的溫度環境下精確的描述出帶對帶穿透電流。我們可以從模擬與量測的結果中得到印證，在大範圍的偏壓條件下皆極為符合，因此本模型可以精確的預估出帶對帶穿透電流。我們可以利用本模型做一些實際的應用。

At the beginning, we measure the off-state current of the MOS device under different temperatures to make sure the physical mechanism, then we analyze the model of band-to-band tunneling current. Because the former one-dimensional band-to-band tunneling model doesn’t consider the influence of drain concentration and lateral electric field, hence after the comparison between the simulated gate-induced drain leakage current and the measured results, it is found that these results don’t correspond to each other. So we propose a two-dimensional model which not only takes the vertical electric field into consideration but also consider the influence of lateral electric field on the band-to-band tunneling effect. Moreover, the effect of temperature also takes into consideration, therefore the model can describe band-to-band tunneling current precisely under different operation temperatures. The simulated and measured results prove that the developed model is valid for a wide range of bias condition, so it can precisely estimate the band-to-band tunneling current. We can use the developed model in some practical applications.