請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/85877
標題: | 二維材料電洞傳輸特性及元件應用之研究 Studies of hole Transport Properties of Two-Dimensional Materials and Component Applications |
作者: | Che-Yu Wu 吳哲宇 |
指導教授: | 吳育任(Yuh-Renn Wu) |
關鍵字: | 二維材料,第一原理計算,蒙地卡羅法,載子遷移率,二維材料電晶體, 2D materials,first-principles calculations,Monte Carlo method,carrier mobility,2D material transistors, |
出版年 : | 2022 |
學位: | 碩士 |
摘要: | 本論文研究是透過第一原理計算取得二維材料的基本材料參數,能帶,有效質量等。在能帶中,K 谷以及 Γ 谷之間的能量高低差大小是影響傳輸特性的重要因素之一。並且考慮二維材料通道被高介電係數的介電層所包覆時所產生的遠程聲子散射。透過蒙地卡羅法來討論過渡金屬硫屬化合物的傳輸特性,模擬二維材料的電洞遷移率。四種材料的電洞遷移率在介電層 Al2O3 的影響下,在低電場下MoS2,MoSe2,WS2,WSe2 分別具有 100,66,128,92 cm2/V⋅s 的電洞遷移率。將所取得的材料參數帶入到所設計的結構來模擬二維通道電晶體的元件特性。評估不同元件在蕭特基位能障礙大小 0.0 eV 到 0.5 eV 所具有的接觸電阻,並且透過在底部閘極施加偏壓下減少其接觸電阻,進而增加電流大小。在改變蕭特基位能障礙大小下,其亞閾值擺幅趨勢在 60 mV/dec 左右,並且隨著蕭特基位能障礙上升跟著些微上升,但還是低於 IRDS 近年來的要求,75 mV/dec。在設定蕭特基障礙為 0 eV 的情況下,因 WS2 有最好的 mobility,具有導通電流 587 μA/μm。但根據二維材料的電子親和力和帶隙以及接觸金屬的功函數可以知道 WS2 和 MoS2不適合做為 PFET 的通道。而 WSe2 和 MoSe2 較適合做為 PFET 的通道。且在同樣接觸 Pt 金屬的時候,因其能帶關係,四種材料中 WSe2 具有最高的的導通電流563 μA/μm,符合 IRDS 2025 年要求的導通電流達到 546 μA/μm。因此 WSe2 是最具有潛力的 PFET 通道材料。並且我們了解在不同等效接觸電阻數量級下所對應到的導通電流數量級。 The research is to obtain the basic material parameters of two-dimensional materials through first-principles calculation. In the energy band, the energy difference between the K valley and the Γ valley is one of the important factors affecting the transmission characteristics. Considering the remote phonon scattering that occurs when a 2D material channel is coated with a high- dielectric layer, it is also one of the important scatterings that affect the hole mobility. The transport properties of transition metal dichalcogenides are discussed by the Monte Carlo method to simulate the hole mobility of two-dimensional materials. The hole mobilities of MoS2, MoSe2, WS2, WSe2 under the influence of Al2O3 are 100, 66, 128, and 92 cm2/V⋅s at low electric fields. The obtained material parameters are applied to the designed structure to simulate the element properties of two-dimensional channel transistors. The contact resistance of different components at source/drain with a Schottky barrier value of 0.0 eV to 0.5 eV was evaluated, and the current was increased by applying a bias voltage at the bottom gate to reduce the contact resistance. Under different Schottky barrier values, the subthreshold swing is around 60 mV/dec, and it increases slightly with the increase of Schottky barrier. But it is still lower than the requirement of IRDS in recent years, 75 mV/dec. With the Schottky barrier set to 0 eV, because WS2 has the best mobility, its Ion is 587 μA/μm. Finally, according to the electron affinity and band gap of the two-dimensional material and the work function of the contact metal, it can be known that WS2 and MoS2 are unsuitable for PFET channels. WSe2 and MoSe2 are more suitable as PFET channels. And when TMDs are all in contact with Pt metal, because of the energy band relationship, WSe2 has the highest Ion, which is 563 μA/μm, which meets the Ion required by IRDS 2025, reaching 546 μA/μm. Therefore, WSe2 is the most potential PFET channel material. In addition, we have a better understanding of the corresponding Ion current orders of magnitude under different equivalent contact resistance orders. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/85877 |
DOI: | 10.6342/NTU202203764 |
全文授權: | 同意授權(全球公開) |
電子全文公開日期: | 2022-09-26 |
顯示於系所單位: | 光電工程學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
U0001-2109202220251600.pdf | 5.67 MB | Adobe PDF | 檢視/開啟 |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。