現今電子元件追求低功耗、低成本並維持高效能，而在元件尺寸微縮的過程中面臨到的物理極限，例如短通道效應，為了克服元件微縮到達物理極限之限制，以具負電容效應之鐵電材料(Ferroelectric, FE) 可以產生負電容效應的特性，使得次臨界斜率SS(Subthreshold Swing)低於物理極限60 mV/decade，可以解決此一物理極限問題，並使元件能在較低電壓下達到快速開啟之效果，實現未來5G、人工智慧物聯網(AIOT)的超低功耗之積體電路應用。

我們研究負電容鰭式場效電晶體，而我們在元件的閘極介電層上疊上2奈米、3奈米以及5奈米厚之氧化鉿鋯的超薄薄膜並進行原子尺度的特徵分析。首先，我們使用同步輻射（1.5 GeV，波長為0.155nm）的高分辨率之低掠角入射X光繞射（GI-XRD），其結果證實了HZO薄膜具有明顯的正交晶相。即使是2-nm厚的氧化鉿鋯薄膜也具有這種晶相。此外，我們也使用了奈米電子束繞射（NBD）去證實了存在於氧化鉿鋯(HZO)中的正交晶相。與對照組HfO2-FinFET相比，我們提出的負電容鰭式場效電晶體(NC-FinFET) 表現出低於60 mV / decade的次臨界斜率（SS）以及幾乎沒有遲滯現象產生。Id-Vg電性曲線圖表現出低漏電流(Ioff)和高驅動電流(Ion)，具有高開關電流比(Ion/Ioff)；不僅如此，根據實驗數據顯示，幾乎沒有汲極引致能障下降（DIBL）的現象產生。當閘極長度(LG)> 通道寬度(WCh)（LG / WCh> 1）時，大多數NC-FinFET的 SS值低於60 mV / decade。 此負電容鰭式場效電晶體擁有優良的電性以及相當簡易的製程，因此在低功耗功率元件的應用非常具有潛力。若未來元件微縮到達極限，負電容場效電晶體將會在半導體的演進中扮演重要角色。

Nowadays, we pursue low power consumption, low cost and maintaining high performance on our electronic devices and encountering the physical limits in the process of devices’ scaled-down, such as short channel effects. In order to overcome the limitation of device miniaturization reaching physical limits, we use Ferroelectric material which can produce negative capacitance effect, so that the SS (Subthreshold Swing) lower than the physical limit of 60 mV/decade may solve this problem of physical limit as well as let the devices be turned on rapidly at lower voltages. In the future, ultra-low power integrated circuit applications such as 5G and artificial intelligence Internet of Things (AIOT) can be realized.

We report ultra-thin 2-nm-, 3-nm-, and 5-nm-thick Hf0.5Zr0.5O2 (HZO) thin films as a gate insulator using atomic-level characterization of Negative Capacitance Fin Field-Effect-Transistors (NC-FinFET). First, the results of high-resolution grazing incidence X-ray diffraction (GI-XRD) using synchrotron radiation (1.5 GeV with a wavelength of 0.155 nm) revealed that the HZO thin films had a clear orthorhombic (o) crystalline phase; even the 2-nm-thick HZO film had this type of phase. In addition, nano beam diffraction (NBD) confirmed the o phase in HZO. The proposed NC-FinFETs exhibited sub-60 mV/decade subthreshold slopes (SS) and nearly hysteresis-free behaviors compared with baseline HfO2-FinFETs. The ID-VG transfer curves exhibited low Ioff and high Ion, and were nearly free of drain-induced barrier-lowering (DIBL) in the statistical results. When LG > WCh (LG/WCh>1), most of the NC-FinFETs exhibited SS < 60 mV/decade. The Negative Capacitance FinFET has excellent electrical properties and fairly simple process, so the application of low power device is promising. If the devices shrinkage reaches its limit in the future, the Negative Capacitance Field Effect Transistor will play an important role in the evolution of the semiconductor.

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