Please use this identifier to cite or link to this item:
Chemical Lift-Off processes for blue light-emitting diodes
Light Emitting Diode
|引用:|| H. Goto, S. W. Lee, H. J. Lee, H.-J. Lee, J. S. Ha, M. W. Cho, and T. Yao, “Chemical lift-off of GaN epitaxial films grown on c-sapphire substrates with CrN buffer layers” Phys. Status Solidi C 5 (2008) 1659.  D. J. Rogers, F. Hosseini Teherani, A. Ougazzaden, S. Gautier, L. Divay, A. Lusson, O. Durand, F. Wyczisk, G. Garry, T. Monteiro, M. R. Correira, M. Peres, A. Neves, D. McGrouther, J. N. Chapman, and M. Razeghi, “Use of ZnO thin films as sacrificial templates for metal organic vapor phase epitaxy and chemical lift-off of GaN” Appl. Phys. Lett. 91 (2007) 071120.  J. Park, K. M. Song, S. R. Jeon, J. H. Baek, and S. W. Ryu, “Doping selective lateral electrochemical etching of GaN for chemical lift-off” Appl.Phys. Lett. 94 (2009) 221907.  J. S. Ha, S. W. Lee, H. J. Lee, H. J. Lee, S. H. Lee, H. Goto, T. Kato, K. Fujii, M. W. Cho, and T. Yao, “The Fabrication of Vertical Light-Emitting Diodes Using Chemical Lift-Off Process “ IEEE Photonics Technol. Lett. 20 (2008) 175.  Y. S. Wu, J. H. Cheng, W. C. Peng, and H. Ouyang,” Effects of laser sources on the reverse-bias leakages of laser lift-off GaN-based light-emitting diodes” Appl. Phys. Lett. 90 (2007) 251110.  K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High Output Power InGaN Ultraviolet Light-Emitting Diodes Fabricated on Patterned Substrates Using Metalorganic Vapor Phase Epitaxy” Jpn. J. Appl. Phys. 40 (2001) 583.  A. David, T. Fujii, R. Sharma, K. Mcgroody, S. Nakamura, S. P. DenBaars, E. L. Hu, and C. Weisbuch, “Photonic-crystal GaN light-emitting diodes with tailored guided modes distribution” Appl. Phys. Lett. 88 (2006) 061124.  H. K. Cho, J. Jang, J. H. Choi, J. Choi, J. Kim, J. S. Lee, B. Lee, Y. H. Choe, K. D. Lee, S. H. Kim, K. Lee, S. K. Kim, and Y. H. Lee, “Light extraction enhancement from nano-imprinted photonic crystal GaN-based blue light-emitting diodes” Opt. Express 14 (2006) 8654.  H. G. Kim, M. G. Na, H. K. Kim, H. Y. Kim, J. H. Ryu, T. V. Cuong, and C. H. Hong, “Effect of periodic deflector embedded in InGaN/GaN light emitting diode”, Appl. Phys. Lett. 90 (2007) 261117.  T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening” ,Appl. Phys. Lett. 84 (2004) 855.  D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y.Huang, C. F. Lin, and R. H. Horng,” Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template” ,Appl. Phys. Lett. 89 (2006) 161105.  J. H. Lee, N. S. Kim, D. Y. Lee, and J. H. Lee,” Effect of Residual Stress and Sidewall Emission of InGaN-Based LED by Varying Sapphire Substrate Thickness “ IEEE Photonics Technol. Lett. 21 (2009) 1151.  S. C. Hsu, B. J. Pong, W. H. Li, T. E. Beechem, S. Graham, and C. Y. Liu,” Stress relaxation in GaN by transfer bonding on Si substrates “ Appl. Phys. Lett. 91 (2007) 251114.  H. Jia, L. Guo, W. Wang, and H. Chen, ” Recent Progress in GaN-Based Light-Emitting Diodes” Adv. Mater. 21 (2009) 4641.  J. H. Cheng, Y. S. Wu, W. C. Liao, and B. W. Lin,” Improved crystal quality and performance of GaN-based light-emitting diodes by decreasing the slanted angle of patterned sapphire “ Appl. Phys. Lett. 96 (2010) 051109.  C. C. Pan, C. H. Hsieh, C. W. Lin, and J. I. Chyi,” Light output improvement of InGaN ultraviolet light-emitting diodes by using wet-etched stripe-patterned sapphire substrates” J. Appl. Phys. 102 (2007) 084503.  J. H. Lee, D. Y. Lee, B. W. Oh, and J. H. Lee,” Comparison of InGaN-Based LEDs Grown on Conventional Sapphire and Cone-Shape-Patterned Sapphire Substrate “ IEEE Trans. Electron Devices 57 (2010) 157.  R. Nowak, M. Pessa, M. Suganuma, M. Leszczynski, I. Grzegory, S. Porowski, and F. Yoshida,” Elastic and plastic properties of GaN determined by nano-indentation of bulk crystal “ Appl. Phys. Lett. 75 (1999) 2070.  R. Navamathavan, Y. T. Moon, G. S. Kim, T. G. Lee, J. H. Hahn, and S. J. Park,” ‘Pop-in’ phenomenon during nanoindentation in epitaxial GaN thin films on c-plane sapphire substrates “ Mater. Chem. Phys. 99 (2006) 410.|
In this research, we focus on to separate the InGaN-based light emitting diodes (LEDs) and sapphire through chemical and mechanical lift-off (CLO) technique. There are three kinds of the CLO technique will be discussed, First, InGaN-based light-emitting diodes (LEDs) grown on triangle-shaped patterned sapphire substrates were separated through a chemical lift-off process by laterally etching an AlN sacrificial layer at the GaN/sapphire substrate interface. After the epitaxial growth, an air-void structure was observed at the patterned region on the sapphire substrate that provided an empty space to increase the lateral etching rate of the AlN buffer layer. The lateral etching rate of the AlN buffer layer was calculated at 10μm/min for the 100μm-width LED chip that was lifted off from the sapphire substrate. A triangular-shaped hole structure and a hexagonal-shaped air-void structure were observed on the lift-off GaN surface that was transferred from the patterned sapphire substrate. Comparing to the LED/sapphire structure, a peak wavelength blueshift phenomenon of the micro-photoluminescence spectra was observed on the lifted off LED chip caused by the release of a compressive strain at the GaN/sapphire substrate interface. The chemical lift-off process was achieved by using an AlN buffer layer as a sacrificial layer in a hot potassium hydroxide solution. Second, an epitaxial layer of an InGaN light-emitting diode (LED) structure was separated from a truncated-triangle-striped patterned-sapphire substrate through a CLO process. A crystallographic stable and terminated V-shaped GaN grooved pattern was observed on the lift-off GaN surface. A peak wavelength blueshift phenomenon of the micro-photoluminescence spectrum was observed on the lift-off LED epitaxial layer (440.7 nm) compared with the LED/sapphire structure (445.8 nm). The free-standing LED epitaxial layer with a 453nm electroluminescence emission spectrum was realized through a CLO process with the potential to replace the traditional laser lift-off process for vertical LED applications. Last, we separated from a GaN/sapphire structure by inserting sacrificial Si-doped InGaN/GaN superlattice layers through a chemical–mechanical lift-off (CMLO) process. The CMLO process consisted of a band-gap-selective photoelectrochemical lateral wet etching process and a mechanical lift-off process. A lower elastic modulus and hardness of the lateral-etched. LED structure were measured compared with the conventional LED structure, which indicated a weak mechanical property of the treated LED structure. The photoluminescence blue-shift phenomenon and the Raman red shift phenomenon indicated that the compressive strain from the bottom GaN/sapphire structure was released through the CMLO process.
|Appears in Collections:||材料科學與工程學系|
Show full item record
TAIR Related Article
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.