Research of Quantized Current Effect with Work Function Variation in Tunnel-field Effect Transistor

초록

In this paper, an investigation has been performed to analyze the relation between oncurrent (I-on) and gate work function variation (WFV) in the tunnel field-effect transistor (TFET) with help of technology computer-aided design (TCAD) simulation. Comparing the I-on of metal-oxidesemiconductor field-effect transistor (MOSFET) and TFET, it is observed that the quantized current level of TFET is depending on channel bias conditions and width of channel. Therefore, we analyze this current quantization within three categorizations. Firstly, the Ion is quantized by applied level of high gate bias (V-GS). At high VGS, the I-on is quantized well following gate WF value near the source-side because the tunnel barrier is made in the specific area by junction between gate and source. However, at low V-GS, a lot of current levels are confirmed because almost half of the channel is affected by WFV due to the large tunneling width. Secondly, the quantized I-on variation by WFV is also affected by level of V-DS. Because the influence of the channel potential is differed by induced electron density. Finally, the Ion is quantized by width of device. Because, considering metal grain size, the WF value near the source-side is determined only several levels. Then, related with the width, we quantitatively analyzed the quantization of I-on, and based on the probability of WFVs, it is confirmed that the phenomenon of current quantization in TFET is predictable.

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