以金屬有機化學氣相沉積製備氮化鎵/氮化鋁/氮化鋁鎵之製程模擬研究

Modeling study on metal organic chemical vapor deposition for GaN/AlN /AlGaN film

林家葳(Jia-Wei Lin)

指導教授 ： 魏大欽

中原大學/工學院/化學工程研究所/碩士(2019年)

https://doi.org/10.6840/cycu201900732

摘要

本研究建立氮化鎵、氮化鋁及氮化鋁鎵之金屬有機化學氣相沉積反應機制，以Chemkin軟體之完美攪拌反應器模型求解，探討不同參數對製程之影響，並使其能夠精準預測真實結果。
在氮化鎵研究中，首先利用本實驗室先前所建立之反應機制進行求解，發現在壓力上升的情況下，鍍膜速率會隨之上升，與真實結果之趨勢相反。本研究重新建立一套反應機制，並加入氫氣輔助表面物種脫附之反應式，使模型與實驗結果之趨勢吻合。
由氮化鋁模型結果可得知，於氣相生成之氮鋁加合物同時扮演於表面成膜以及氣相成核之主要物種。當溫度到達質傳限制區間，鍍膜速率會隨之上升，到達一定溫度後，主要物種傾向在氣相當中聚合，不與表面進行吸附，造成在高溫的區間，鍍膜速率逐漸下降。在調整壓力參數方面，如同氮化鎵模型，加入氫氣輔助表面物種脫附之反應式，而從模型結果可得知，氣相成核之現象在壓力上升條件下更為明顯，也會使得鍍膜速率下降。
最後將上述兩個模型結合，建立氮化鋁鎵模型，由結果可得知，可藉由調整不同操作參數探討其含鋁量及鍍膜速率的的影響，利用不同的氣相進氣鋁鎵比，可明顯地改變固相中的含鋁量。本研究所建立的模型可有效地探討金屬有機化學氣相沉積中複雜的化學反應機制。

關鍵字

金屬有機化學氣相沉積 ； 動力學模型 ； 氮化鋁鎵

並列摘要

In this study, numerical analysis of metal organic chemical vapor deposition of GaN / AlN / AlGaN process was performed by zero-dimension (0-D) chemical kinetics modeling. Suitable reaction mechanisms for GaN / AlN / AlGaN was established in order to investigate the influence of different process parameters.
With pressure increase, it was found that the previous GaN model prediction couldn’t agree with the experiment data. We established a new GaN mechanism and added desorption reaction to agree with experimental findings.
It could be realized from the results of the AlN model that the nitrogen-aluminum adducts formed in the gas phase simultaneously play a major role in surface film formation and gas phase nucleation. When the temperature reaches the mass transfer limit region, the growth rate will increase. After reaching a certain temperature, the main species tend to polymerize in the gas phase, and do not adsorb on the surface, resulting in a gradual decrease in the growth rate in the high temperature range.
Finally, we combine both GaN and AlN models to establish the AlGaN model and investigate the effects of the inlet gas ratio, temperature and pressure to the AlGaN growth rate and aluminum composition of the film. In conclusion, this study has successfully developed three models to simulate the complex physical-chemical process in MOCVD.

並列關鍵字

MOCVD ； kinetic model ； AlGaN

參考文獻

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