以電鍍銅法製備薄膜式氮化鎵發光二極體元件及其應力分析

Stress Analysis of Transferred Thin-GaN Light-Emitting Diode Fabricated by Cu Electroplating

吳仕勤(Shin-Chin Wu)

指導教授 ： 張正良

共同指導教授 ： 許世杰

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2012年)

https://doi.org/10.6846/TKU.2012.01040

摘要

本實驗乃利用電鍍(Electroplating)技術取代晶圓鍵合(Wafer Bonding)以達到基板轉移之目的，此技術可達到低成本、解決良率問題、減少晶圓鍵合衍生出的熱應力等優點，並利用雷射剝離(Laser Lift-Off)技術移除導電性、散熱性均不佳的藍寶石基板(Al2O3, Sapphire)，以製作薄膜式氮化鎵發光二極體(Thin-GaN LED)之元件。此外，藉由拉曼(Raman)量測及Kozawa方程式計算來探討成長在不同電鍍銅基板厚度下的氮化鎵磊晶層之應力變化，並獲得磊晶層之最小殘留應力，且透過改變氮化鎵磊晶層應力來減少量子侷限史塔克效應(Quantum-Confined Stark Effect, QCSE)以達到增進氮化鎵發光二極體元件之內部量子效率(Internal Quantum Efficiency, IQE)為目的。最後，光致發光光譜(Photoluminescence, PL)用於分析磊晶層能隙變化。
結果發現，波長出現藍位移，如此證明利用基板轉移的方式使磊晶層之應力狀態被獲得改善，並進一步避免了QCSE現象及提升內部量子效率。

關鍵字

發光二極體 ； 電鍍 ； 應力分析 ； 量子侷限史塔克效應 ； 內部量子效率

並列摘要

We use electroplating technique instead of wafer bonding, because the technique can achieve cost saving、solve yield issues and avoid thermal stress derived from the wafer bonding. Then, laser lift-off technique to remove sapphire substrate which has low thermal and electrical conductivity. In this way, we can get the complete thin-GaN LED structure.
Also, we apply this structure to analyze QCSE phenomena under various thicknesses of copper substrate to reach the goal of under various thicknesses of copper substrate and further enhance the internal quantum efficiency. Besides, we use Raman measurement and Kozawa equation to calculate the changes of the compressive stress of GaN epitaxial layer. PL spectra is adopted to prove the changes of energy bandgap of GaN epitaxial layer.
Finally, we find the blue shift and confirm that it can avoid QCSE phenomena by changing stress-state of GaN epilayer.

並列關鍵字

Light-Emitting Diode ； Electroplating ； Stress Analysis ； Quantum-Confined Stark Effect ； Internal Quantum Efficiency

參考文獻

[1] E. F. Schubert “Light-Emitting Diodes” 2nd ed., Cambridge University Press, New York (2006)

[2] I. Akasaki and H. Amano “Crystal growth and conductivity control of group III nitride semiconductors and their application to short wavelength light emitters” Jpn. J. Appl. Phys., vol. 36, pp. 5393-5408 (1997)

[3] Y. Honda, Y. Iyechika, T. Maeda, H. Miyakei and K. Hiramatsui “Transmission Electron Microscopy Investigation of Dislocations in GaN Layer Grown by Facet-Controlled Epitaxial Lateral Overgrowth” Jpn. J.Appl. Phys., vol. 40, pp. L309–L312 (2001)

[4] William A. Melton and Jacques I. Pankove ”GaN growth on sapphire” Journal of Crystal Growth, Vol. 178, No. 1, pp. 168-173 (1997)

[6] S. Nakamura, M. Senoh, N. Iwasa and S. Nagahama, “High-power InGaN single-quantum-well structure blue and violet light-emitting-diodes” Applied Physics Letters, vol. 67, pp. 1868 (1995)