Estimation of Threshold Voltage in SiC Short-Channel MOSFETs
Estimation of Threshold Voltage in SiC Short-Channel MOSFETs
复制标题
SiC 短沟道 MOSFET 阈值电压的估算
DOI：
10.1109/ted.2018.2837028
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发表时间：
2018
影响因子：
3.1
通讯作者：
T. Kimoto
中科院分区：
文献类型：
--
作者：
K. Tachiki;T. Ono;Takuma Kobayashi;Hajime Tanaka;T. Kimoto
在本文中，研究了SiO₂/SiC界面处高密度陷阱对短沟道效应的影响，并提出了一个描述阈值电压（即给定漏电流下的栅极电压）与沟道长度相关性的模型。首先，我们通过将计算得到的栅极特性与实验数据进行拟合，确定了4H - SiC n沟道MOSFET中的界面态密度和固定电荷密度，并从所得结果中获取了被俘获电子的密度。然后，考虑到由于耗尽层的形成，大部分被俘获电子在漏端附近发射，我们计算了阈值电压。即使阈值电压的定义发生变化，所提出的模型计算出的阈值电压与沟道长度的相关性也与实验结果吻合良好。考虑固定电荷和被俘获电子电荷的当前模型能够估算4H - SiC短沟道MOSFET中的阈值电压。
In this brief, the influence of high-density traps at the SiO2/SiC interface on short-channel effects was investigated, and a model describing channel length dependence of the threshold voltage (i.e., the gate voltage at a given drain current) is proposed. First, we determined the densities of interface states and fixed charge in 4H-SiC n-channel MOSFET by fitting the calculated gate characteristics to the experimental data, and acquired the density of trapped electrons from the obtained results. Then, we calculated the threshold voltage by considering that the majority of the trapped electrons are emitted near the drain end due to formation of a depletion layer. The channel length dependence of the threshold voltage calculated by the proposed model showed a good agreement with the experimental results even when the definition of threshold voltage was changed. The present model taking account of the fixed charge and of the trapped electron charge enables the estimation of the threshold voltage in the 4H-SiC short-channel MOSFETs.