低溫濺鍍單晶氮化鋁薄膜特性與成長機制探討

Study of low temperature sputtered AlN thin film: characteristics and growth mechanism

許維凡(Wei-Fan Hsu)

指導教授 ： 高慧玲

中原大學/工學院/電子工程研究所/碩士(2014年)

https://doi.org/10.6840/cycu201400339

摘要

氮化鋁（Aluminum Nitride, AlN）為6.2 eV之直接能隙半導體材料，除了常用於光電半導體產業之晶種層之外，亦可用於製造深紫外光發光二極體（light-emitting diodes, LEDs）或金屬-半導體-金屬（metal-semiconductor- metal, MSM）元件與表面聲波（surface acoustic wave, SAW）元件之紫外光感測器，因而具備發展潛力。
本研究以低溫濺鍍法分別製備單晶AlN薄膜於MOCVD沉積的高品質 900 nm AlN/sapphire、市售20 nm AlN/sapphire、c-plane sapphire與MgO(111)基板上，以XRD與PL比較其品質，並透過SEM、TEM與structure zone model、物理氣相沉積（physical vapor deposition, PVD）成核理論探討其沉積機制。
結果顯示低溫濺鍍環境下，AlN薄膜品質受底材表面粗糙度以及與底材之晶格不匹配度影響甚鉅，並且前者更為重要。MgO(111)基板退火後除了可改善表面粗糙度之外，亦會於部分區域產生原子級的平坦度，使後續沉積的AlN薄膜以2D模式成核與生長，因而大幅提升該區晶粒大小。

關鍵字

成長機制 ； 氧化鎂 ； 單晶氮化鋁 ； 低溫濺鍍 ； 光激螢光

並列摘要

Aluminum nitride (AlN) is a semiconductor material with direct band gap of 6.2 eV. It has been commonly used as a nucleation layer in the opto-semiconductor applications. Moreover, AlN is very attractive since it can be employed to fabricate deep-ultraviolet light-emitting diodes (LEDs) as well as metal-semiconductor-metal (MSM) and surface acoustic wave (SAW) devices for ultraviolet detection potentially.
In this study, single crystalline AlN thin film has been grown using low-temperature sputtering system on various substrates, including MOCVD-grown high quality AlN(900nm)/sapphire, commercial AlN(20nm)/sapphire, c-plane sapphire, and MgO(111). The crystal structure and quality of AlN has been investigated by XRD and PL. The growth mechanism is studied using SEM, TEM, structure zone model (SZM), and the nucleation theorem of physical vapor deposition (PVD).
The results show that the quality of AlN thin film is affected by both substrate surface roughness and lattice mismatch between AlN and substrates, with the former being more critical. The surface roughness of MgO(111) substrate may be reduced by high temperature annealing, and the partially atomically smooth region was obtained. The smoothness brings about the 2D nucleation and 2D growth of AlN deposition, and thus increases the grain size significantly at that region.

並列關鍵字

single crystalline AlN ； low-temperature sputtering ； photoluminescence ； MgO ； growth mechanism

參考文獻

[14] 蔡明利，《以濺鍍法沉積矽摻雜氮化鋁薄膜之可行性探討》，碩士論文，中原大學電子研究所，民101年。

[1] Y. Taniyasu, M. Kasu, and T. Makimoto, “An aluminum nitride light-emitting diode with a wavelength of 210 nanometers”, Nature (London) 441(18), 325–328 (2006).

[2] J. Jasinski, Z. Liliental-Weber, Q. S. Paduano, and D. W. Weyburne, “Inversion domains in AlN grown on sapphire(0001)”, Applied Physics Letters 83, 2811–2813 (2003).

[3] M. Shatalov, Mikhail, V. Adivarahan, and A. Khan, “Room-Temperature Stimulated Emission from AlN at 214nm”, Japanese Journal of Applied Physics 45(49), L1286–1288 (2006).

[4] K. Uehara, C-M. Yang, T. Furusho, S-K. Kim, S. Kameda, H. Nakase, S. Nishino, and K. Tsubouchi, “AlN epitaxial film on 6H-SiC(0001) using MOCVD for GHz-band SAW devices”, IEEE Ultrasonics Symposium 1, 905–908 (2003).