術語“單層材料”或“二維材料”指的是由原子單層組成的結晶固體。在某些情
況下，一些層之間弱相互作用的薄膜也被稱為“二維材料”，當層間相互作用明
顯弱於單層內部時，會導致獨特的準二維特性。例如，儘管由多個層組成，多
層石墨烯仍然被認為具有二維結構[1]。這些二維材料對局部幾何形狀非常敏
感，易於透過吸附物進行修飾。
二維材料具有高遷移率、高導電性、優越的機械強度和長自旋擴散長度等獨
特優勢，使其適用於自旋電子裝置。然而，它們並不普遍優於體材料，面臨著
與尺寸、可擴展性、穩定性、整合、成本和特異性等相關的挑戰。
在本研究中，我們獲得了過渡金屬二硫化物（TMDCs）材料[2]，包括來
自國立成功大學(NCKU)呂欽山教授磊晶實驗室的NiTe2[3]和來自台灣半導體
製造公司(TSMC)的WS2[4]。因此，我們關注TMDCs家族。TMDCs的化學式
為MX2，其中M是過渡金屬，X是硫族元素，由於其獨特的帶隙、優異的光吸
收[5]、強烈的限域效應、高電子遷移率[6]和層間耦合[7]等特性，TMDCs表現出
多樣的性質和潛在應用。它們在電子裝置、奈米技術、表面科學和能量儲存等
領域具有應用潛力。
在表面科學領域，掃描穿隧顯微術(Scanning Tunneling Microscopy, STM)作
為一種強大的工具，提供了對實空間成像的原子分辨率，從而揭示了表面科
學之地形和形態的洞察，並可訪問局部電子性質[8]。與XPS和PES等技術相
比，STM在捕捉非週期性修改方面表現出色，展示了其在研究二維材料方面的
強大優勢。
此外，我們提出了一個基於Arduino的STM系統自動監控流程，簡化和最佳
化加熱、壓力測量和溫度監控等中間步驟。此方法涉及使用DAC、ADC、電源
和其他監控項目進行有效的控制和監控，確保STM操作更加順利和有效率。
總體而言，本研究深入探討了二維材料的獨特性質和潛力，重點關
注TMDCs，並強調了STM在表面科學研究中的關鍵作用，提高了我們對這些材
料在各種技術應用中的理解和利用。
6

The term ’single-layer materials’ or ’2-D materials’ refers to crystalline solids comprising a monolayer of atoms. In some cases, a few layers of weakly interacting films are also referred to as ’2-D materials’ when the interlayer interaction is significantly weaker than within the single layer, leading to distinct quasi 2-D
properties. For example, despite consisting of multiple layers, multilayer graphene is still considered to possess a 2-D structure. These 2-D materials exhibit high sensitivity to local geometry, making them easily modifiable by adsorbates.
2-D materials offer unique advantages such as high mobility, conductivity, mechanical strength, and long spin diffusion length, making them suitable for spintronic devices. However, they aren’t universally superior to bulk materials, facing challenges related to size, scalability, stability, integration, cost, and specificity.
In this study, we got the Transition Metal Dichalcogenides (TMDCs) materials.
They are NiTe2 from Prof. Ching-Shan Lue’s Epitaxy Laboratory in National Cheng Kung University (NCKU) and WS2 from Taiwan Semiconductor Manufacturing Company (TSMC). Therefore, we focus on TMDCs family. TMDCs, with the formula MX2, where M is a transition metal and X is a chalcogen, demonstrate
diverse properties and potential applications due to their distinct band gap, excellent optical absorption, strong confinement effect, high electron mobility, and interlayer coupling. They are useful in our electronics, nanotechnology, surface science, and enery storage, etc.
In the realm of surface science, Scanning Tunneling Microscopy (STM) emerges as a powerful tool, providing atomic resolution for real-space imaging, thereby giving topography, and morphology insights and access local electronic properties.
Compared to techniques like XPS and PES, STM excels in capturing non-periodic modifications, showcasing its strength in investigating 2-D materials.
Additionally, we present an Arduino-based automated monitoring process for STM systems, streamlining and optimizing intermediate steps like bake-out, pressure measurement, and temperature monitoring. This approach involves utilizing DAC, ADC, Power Supply, and additional monitoring projects for efficient control and monitoring, ensuring smoother and effective STM operation.
Overall, this study delves into the distinct properties and potential of 2-D materials, focusing on TMDCs, and emphasizes the pivotal role of STM in surface science investigations, enhancing our understanding and utilization of these materials in diverse technological applications.

Abstract 4
中文摘要6
Acknowledgement 7
1 Introduction 8
2 Theory 10
2.1 Tunneling theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2 STM principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2.1 Bardeen Theory . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2.2 Constant current/height mode . . . . . . . . . . . . . . . . . 17
3 Instrumentation 19
3.1 Omicron VT-STM . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2 Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.2.1 Rotary Pump . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.2.2 Turbomoleculer Pump . . . . . . . . . . . . . . . . . . . . . 23
3.2.3 Ion Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.2.4 Titanium Sublimation Pump . . . . . . . . . . . . . . . . . . 25
3.3 Chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.3.1 Load-Lock Chamber . . . . . . . . . . . . . . . . . . . . . . 26
3.3.2 Preparation Chamber . . . . . . . . . . . . . . . . . . . . . . 26
3.3.3 STM Chamber . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.4 Normal Temperature Environment . . . . . . . . . . . . . . . . . . 27
4 Arduino Project 28
4.1 Project Task: Recording of Pressure . . . . . . . . . . . . . . . . . . 29
4.2 Arduino theory application . . . . . . . . . . . . . . . . . . . . . . . 31
4.2.1 Arduino Theory . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.2.2 Arduino Application . . . . . . . . . . . . . . . . . . . . . . 38
4.3 Digital-to-Analog Convertor . . . . . . . . . . . . . . . . . . . . . . 39
4.3.1 Operating principle of I2C . . . . . . . . . . . . . . . . . . . 39
4.3.2 1 channel DAC control . . . . . . . . . . . . . . . . . . . . . 42
4.3.3 2 channels DAC communication . . . . . . . . . . . . . . . . 44
4.3.4 Intergrated Arduino box . . . . . . . . . . . . . . . . . . . . 45
4.3.5 Voltage division rule and Manual linear correction . . . . . . 46
4.3.6 Omicron ion-gauge recorder . . . . . . . . . . . . . . . . . . 48
4.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5 Experiment 53
5.1 Well-known 2-D material . . . . . . . . . . . . . . . . . . . . . . . . 53
5.1.1 Si(111) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.1.2 Highly oriented pyrolytic graphite (HOPG) . . . . . . . . . . 59
5.2 TMDCs materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.2.1 WS2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.2.2 NiTe2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Summary 95
6 Appendix 96
6.1 Daily Working Table . . . . . . . . . . . . . . . . . . . . . . . . . . 96
6.2 DAC Arduino code . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6.3 Unisoku Multi-gauge Arduino code . . . . . . . . . . . . . . . . . . 100
6.4 Omicron preparation ion gauge GP-370 Arduino code . . . . . . . . 103
6.5 Omicron STM ion gauge PGC2D Arduino code . . . . . . . . . . . 104

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