鉬化物薄膜之沈積及分析

Deposition and Analyses of the Thin Film of Molybdenum Compound

阮至緯

指導教授 ： 游萃蓉

國立清華大學/工學院/材料科學工程學系/碩士(2012年)

摘要

在本研究中，主要專注於成長兩種不同之鉬化物薄膜及分析，分別為二硫化鉬 (MoS2) 以及二氧化鉬 (MoO2)。二硫化鉬利用磁控濺鍍 (magnetron sputtering) 的方式鍍膜後，在硫蒸氣下以550 °C退火，以提升MoS2的光吸收係數 (absorption coefficient, α) 和結晶性 (crystallinity)。並利用掃描式電子顯微鏡 (SEM) 和穿透式電子顯微鏡 (TEM) 觀察表面形貌及微結構，透過低掠角X光繞射分析儀 (GIXRD) 分析結晶性，利用X-ray光電子能譜儀 (XPS) 進行元素分析，最後利用紫外/可見光吸收光譜儀 (UV-vis) 進行光學性質分析，最後得到與硫蒸氣退火後的MoS2薄膜具有高光學吸收係數 (5.5 104 cm-1)。
二氧化鉬利用兩階段式化學氣相沉積法 (two-steps chemical vapor deposition) 製備，在第一階段中成長三氧化鉬 (MoO3) 之後，於第二階段中使MoO3和硫蒸氣反應後生成MoO2。並利用掃描式電子顯微鏡 (SEM) 觀察表面形貌，透過低掠角X光繞射分析儀 (GIXRD) 分析結晶性，以X-ray光電子能譜儀 (XPS) 進行元素分析，利用霍爾量測系統 (Hall-effect) 量測試片得到電阻率 (9.54 × 10-4 )、載子遷移率 (2.28 cm2 V-1 s-1) 和載子濃度 (5.75 × 104 cm-1)，最後利用紫外/可見光吸收光譜儀 (UV-vis)、光致螢光系統 (PL) 和紫外光光電子能譜儀 (UPS) 做光學性質分析， 得到高光吸收係數 (5.75 104 cm-1) 的MoO2薄膜。

關鍵字

二硫化鉬 ； 二氧化鉬 ； 硫化 ； 退火 ； 三氧化鉬

並列摘要

Molybdenum disulfide (MoS2) and molybdenum dioxide (MoO2) were successfully synthesized and characterized in this work. The molybdenum disulfide film was deposited by magnetron sputter, and then annealed with sulfur powder at the temperature of 550 °C to improve the absorption coefficient and crystallinity. The morphology and microstructure of the MoS2 film was characterized by scanning electron microscope (SEM) and high resolution transmission electron microscopy (HR-TEM). The crystallinity of MoS2 film was also measured by Grazing Incidence X-ray diffraction spectroscopy (GIXRD). The composition of MoS2 film was measured by X-ray Photoelectron Spectroscopy (XPS). The band-gap and absorption spectra were analyzed using UV-visible optical absorption spectroscopy. This work successfully obtained a MoS2 film with high absorption coefficient (5.5 104 cm-1).
The molybdenum dioxide film was grown by two-step chemical vapor deposition. Molybdenum trioxide was synthesized in the first step, and then reacted with sulfur atmosphere in step two. The morphology and microstructure of the MoO2 film was characterized by scanning electron microscope (SEM). The crystallinity of MoO2 film was measured by Grazing Incidence X-ray diffraction spectroscopy (GIXRD). The composition of MoO2 film was measured by X-ray Photoelectron Spectroscopy (XPS). The electric properties of MoO2 film were measured by Hall effect system. The band-gap and absorption spectra were analyzed by using UV-visible optical absorption spectroscopy, Photoluminescence (PL) and Ultraviolet Photoemission Spectrospocy (UPS). This study successfully obtained the molybdenum dioxide with low resistivity (9.54 × 10-4 ), high carrier mobility (2.28 cm2 V-1 s-1), high carrier concentration (4.5 × 1021 cm-3), and high absorption coefficient (5.75 × 104 cm-1).

參考文獻

[3] W. KOEHLER, U.S. Patent No. 1,714,565, 1927

[31] K. M. Garadkar, A. A. Patil, P. P. Hankare, P. A. Chate, D. J. Sathe, S. D. Delekar, MoS2 : Preparation and their characterization, Journal of Alloys and Compounds, 487, 2009, 786–789

[15] W. Chen, L. Q. Mai, Y. Y. Qi, W. Jin, T. Hu, W. L. Guo, Y. Dai, E. D. Gu, One-dimensional oxide nanomaterials through rheological self-assembling, H.P. Ceramics IV, 336-338, 2007, 2128-2133

[4] S. Ghatak, A. N. Pal, A. Ghosh, The Nature of Electronic States in Atomically Thin MoS2 Field-Effect Transistors, ACS Nano, 5, 2011, 7707–7712

[6] S.W. Liu, Y. Divayana, X.W. Sun, Y. Wanf, K.S. Leck, and H.V. Demir, Improved performance of organic light-emitting diodes with MoO3 interlayer by oblique angle deposition, Optical Express, 19, 2011, 4513-4520