不同感應耦合電漿離子蝕刻條件對於控制沉積在藍寶石基板的氮化鎵準垂直型P-i-N二極體的蝕刻平台在元件的電特性表現相關研究

Ion etching of GaN mesas with inductively coupled plasma etching and I-V characteristics of quasi-vertical GaN P-i-N diode grown on sapphire

游家睿(Yu, Chia Jui)

指導教授 ： 謝光前 ； 何充隆

國立清華大學/電機資訊學院/電子工程研究所/碩士(2015年)

摘要

能源危機是近半世紀以來人類所需面臨最大的問題之一。近幾年氮化鎵（Gallium Nitride, GaN）材料的研究及其應用範圍正快速的成長，先天上具備直接能隙與寬能隙的氮化鎵，有較佳的光電轉換效率，以及材料製程穩定性。目前在市面上已有利用氮化鎵材料所製作的發光二極體（LED）或紫外線的偵測器（UV Photodetector）等相關元件。此外，功率元件是另一項氮化鎵材料發展上的優勢，除了上述提到的寬能隙特點外，電子飽和速率高、臨界電場高、熱導率佳等等，都是製作高功率、高頻元件的絕佳優勢。而在功率元件領域中，又以P-i-N接面二極體（P-i-N Diode）、蕭基二極體（Schottky Barrier Diode, SBD）、高速電子遷移率電晶體（High Electron Mobility Transistor, HEMT）等元件為近年來最具發展潛力的研究方向。
本實驗是以P-i-N接面二極體（P-i-N Diode）功率元件為主要討論方向。目前評估功率元件的特性優劣是以巴利加優值（Baliga figure of merit, BFOM）為主要評量方式，它是使用逆向崩潰電壓的平方除以順向導通電阻一次方求得巴利加優值，單位為 。本研究利用改良型感應耦合電漿離子蝕刻系統，調整不同製程參數，控制蝕刻側壁的損傷嚴重程度，將元件依據其受損程度細分為六類。最後找出在電漿射頻功率為200 W、直流電壓功率10 W、腔體壓力0.5 Pa、搭配主要成分為氧化鋁的基板並且控溫在 ，可以獲得最平滑的蝕刻側壁以及最佳的電特性表現同時也具有最高的巴利加優值。
關鍵字：功率元件、感應耦合電漿離子蝕刻系統、氮化鎵

關鍵字

功率元件 ； 感應耦合電漿離子蝕刻系統 ； 氮化鎵

並列摘要

One of the significant problems that we must challenge is that energy crisis in the near future. Concerning gallium nitride that has direct energy gap and wide bandgap, it has a decent photoelectric conversion efficiency and process stability. Currently in the market has produced light emitting diode (LED), ultraviolet photodetector (UV Photodetector), and other related devices with gallium nitride. In addition, another superiority of gallium nitride such as the electron saturation velocity, critical electric field, and good thermal conductivity etc., are beneficial for high-power or high-frequency devices. In the field of high power device, P-i-N junction diode, schottky barrier diode (SBD), and high electron mobility transistor (HEMT) are most promising device lately.
This experiment is mainly used P-i-N junction diode with gallium nitride on sapphire to discuss. We currently make use of the Baliga's figure of merits to determine the characteristics of the power device, and it uses the reverse breakdown voltage squared divided by turn-on resistance obtained figure of merits. In this study, we utilize the improved inductively coupled plasma ion etching system to adjust the different process parameters to classify into six categories based on the severity of the sidewall damage. To sum up, we find out with the improved inductively coupled plasma ion etching system at the RF power 200 (W), DC bias 10 (W), chamber pressure 0.5 (Pa), and used aluminum oxide substrate, so that we can get the most smooth etching sidewall and the best electrical characteristics of performance.
Keywords：power device, inductively coupled plasma ion etching, gallium nitride

並列關鍵字

power device ； inductively coupled plasma ion etching ； gallium nitride

參考文獻

[23] 蘇朝墩. (2004). 專訪世界品質大師田口玄一博士.

[4] B. J. Baliga, "Power Semiconductor-Device Figure of Merit for High-Frequency Applications," Ieee Electron Device Letters, vol. 10, pp. 455-457, Oct 1989.

[6] (2015-07-01). Mohs scale of mineral hardness.

[7] J. Lee, H. Cho, D. C. Hays, C. R. Abernathy, S. J. Pearton, R. J. Shul, et al., "Dry etching of GaN and related materials: Comparison of techniques," Ieee Journal of Selected Topics in Quantum Electronics, vol. 4, pp. 557-563, May-Jun 1998.

[9] D. S. Rawal, H. Arora, B. K. Sehgal, and R. Muralidharan, "Comparative study of GaN mesa etch characteristics in Cl-2 based inductively coupled plasma with Ar and BCl3 as additive gases," Journal of Vacuum Science & Technology A, vol. 32, May 2014.