利用低溫濺鍍法沉積單晶氮化鎵鋁薄膜之研究

Single Crystaling Growth AlGaN by Low Temperature Sputtering

簡宏益(Hung-Yi Chien)

指導教授 ： 高慧玲

中原大學/電機資訊學院/電子工程研究所/碩士(2020年)

https://doi.org/10.6840/cycu202000359

摘要

本論文採用迴旋濺鍍系統低溫濺鍍氮化鎵鋁 (AlxGa1-xN)薄膜於兩種不同組合之基板上(1. WS2/SiO2/Si(100) 2. Sapphire)，先以EDS分析薄膜成分，接者利用X光繞射量測和TEM對薄膜晶體結構與結晶品質做更進一步觀察。

本實驗樣品在EDS量測下皆顯示薄膜成份含有鋁和鎵元素，透過XRD θ-2θ scan量測其Al0.2Ga0.8N薄膜結晶皆為c軸從優取向。首先從Al0.2Ga0.8N/Sapphire XRD Phi-scan的結果可以得知，在Sapphire基板上的氮化鎵鋁薄膜是單晶結構，這點也可以從TEM電子繞射圖證實，不過在明暗場圖和HRTEM則發現薄膜具有不少的缺陷和差排；而Al0.2Ga0.8N/WS2/SiO2/Si(100)雖然從XRD Phi-scan並未發現大面積連續單晶結構。但是在TEM電子繞射圖卻說明薄膜具有局部單晶的特性，最後明暗場圖和HRTEM都充分顯示沉積於WS2/SiO2/Si(100)基板上之薄膜擁有較好的品質，非常接近本實驗室以往成功低溫 (500℃)濺鍍單晶AlN薄膜之品質，因此使用WS2二維材料做為緩衝層，確實可以改善部份原子的排列情形，提升薄膜品質。

關鍵字

單晶氮化鎵鋁 ； 低溫濺鍍 ； 藍寶石基板 ； 二硫化鎢緩衝層 ； Si(100)基板

並列摘要

In this thesis , aluminum gallium nitride (AlxGa1-xN) thin films had been deposited on two different substrates (1. WS2/SiO2 /Si(100) 2. Sapphire) at low temperature using helicon sputtering system. The composition of the thin films was analyzed by EDS and crystal structure was characterized by X-ray diffraction. TEM was used to further investigate the thin film crystal microstructure and microdefects.

The EDS measurement indicates that all samples aluminum and gallium with the composition of Al0.2Ga0.8N. The Al0.2Ga0.8N film crystals measured by XRD θ-2θ scan are all c-axis preferred orientation. From the results of XRD Phi-scan, it shows that Al0.2Ga0.8N films grown on sapphire substrates are single crystalline structure. This was also confirmed from the TEM diffraction pattern. However, in the bright and dark field as well as HRTEM, it was found that the films exhibit a lot of defects and dislocations. In contrast, the Al0.2Ga0.8N film prepared on WS2/SiO2/Si(100) did not show a large area single crystal structure from XRD Phi-scan, yet the TEM diffraction pattern shows that the film is locally single crystalline. The bright and dark field patterns and HRTEM clearly showed that the film deposited on the WS2/SiO2/Si(100) substrate has superior quality than that on sapphire directly. This thesis suggests that using WS2 two-dimensional material as the buffer layer can indeed enhance the atom arrangement and improve the quality of the III-nitride thin film growth.

並列關鍵字

single crystalline AlGaN ； low-temperature sputtering ； Sapphire substrate ； Si(100) substrate

參考文獻

參考文獻

[1] R. Mitova, R. Ghosh, U. Mhaskar, D. Klikic, M.-X. Wang, and A. Dentella, "Investigations of 600-V GaN HEMT and GaN diode for power converter applications," IEEE transactions on power electronics, vol. 29, no. 5, pp. 2441-2452, 2013.

[2] X. Huang, Z. Liu, Q. Li, and F. C. Lee, "Evaluation and application of 600 V GaN HEMT in cascode structure," IEEE Transactions on Power Electronics, vol. 29, no. 5, pp. 2453-2461, 2013.

[3] P. Kung et al., "Kinetics of photoconductivity in n‐type GaN photodetector," Applied physics letters, vol. 67, no. 25, pp. 3792-3794, 1995.

[4] J.-K. Sheu et al., "White-light emission from near UV InGaN-GaN LED chip precoated with blue/green/red phosphors," IEEE Photonics Technology Letters, vol. 15, no. 1, pp. 18-20, 2003.