成功大學博碩士論文系統

簡易檢索 / 詳目顯示

回結果列表

研究生：	陳威志 Chen, Wei-Chih
論文名稱：	應用於氮化銦鎵/氮化鎵發光二極體之新式蝕刻製程 Investigation of a New Etching Process for InGaN/GaN LEDs Fabrication
指導教授：	許渭州 Hsu, Wei-Chou
學位類別：	碩士 Master
系所名稱：	電機資訊學院 - 微電子工程研究所 Institute of Microelectronics
論文出版年：	2006
畢業學年度：	94
語文別：	英文
論文頁數：	43
中文關鍵詞：	氮化鎵、蝕刻
外文關鍵詞：	GaN, Etching
相關次數：	點閱：64 下載：0
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

應用於氮化銦鎵/氮化鎵發光二極體之新式蝕刻製程

陳威志* 許渭州 **

國立成功大學微電子工程研究所
電機工程學系

摘要

在本論文中,我們提出一種可應用在氮化鎵材料上新穎且相對易於實行的光電化學蝕刻法。由於氮化鎵中氮原子與鎵原子極大的鍵結能，以傳統濕式蝕刻方法在氮化鎵中難以得到理想的效果。相較於其他團隊提出之光電化學蝕刻法，本論文中所採用的實驗器材更為容易使用且擁有相對低成本的特點。
光源是一個以頻率2.45 GHZ之微波啟動的紫外光燈管，至於蝕刻液方面本論文則採用了稀薄氫氧化鉀水溶液。
實驗結果發現N型氮化鎵的蝕刻率與氫氧化鉀溶液之莫耳濃度以及氮化鎵中的載子濃度有著極大的關連性。
相對於N型氮化鎵，P型氮化鎵卻無法以相同步驟進行蝕刻。但是蝕刻液卻可在P型試片的表面產生一個粗糙的微型結構，此結果我們將之採用在發光二極體表面粗糙化以提升發光亮度的製程。
經由量測結果發現，雖然二極體之順向偏壓大約提升了0.1伏特;光輸出功率卻增強了10% 。

作者*
指導教授**

Investigation of a New Etching Process for InGaN/GaN LEDs Fabrication

Wei-Chih Chen* Wei-Chou Hsu**

Institute of Microelectronics,
Department of Electrical Engineering
National Chen Kung University
Tainan, Taiwan
R.O.C
Abstract
A novel Photo-Enhanced Chemical etching (so-called “PEC etching”) technique of Gallium Nitride (GaN) is presented and fully investigated. Due to the strong chemical bond of gallium to nitride, it is quite difficult to perform wet etching on GaN and other nitride-based materials.
Compare to other wet etching scheme reported earlier, we report a much easier and cheaper etching scheme in this work. A microwave–initiated UV lamp served as the light source, while dilute Potassium Hydroxide (KOH) solution was used as the etchant. The etching rate of n-GaN was found to be highly dependent of carrier concentration along with molarity (M) of KOH solution. In most cases, n-GaN is readily etched, by contrast to p-GaN where a very rough surface morphology has been made. By applying this surface treatment on InGaN/GaN LEDs, diode forward turn-on voltage was raised by about 0.1V while the light output is 1.1 times of a conventional device.

Author *
Advisor**

Contents
Abstract (Chinese)
Abstract (English)
Chapter 1 Introduction                          1
1-1	Background Research on GaN             1
1-2	Organization                           3

Chapter 2  Measurement Techniques and           Instruments 4                                                                                 
                               
2-1  Inductively Coupled Plasma Reactive Ion Etching (ICP-RIE) 4                                
        2-2  Micro Figure Measuring Instrument (α-step) 5                                           
        2-3  Atomic Force Microscopies (AFM) 5                                       
        2-4  Rapid Thermal Anneal (RTA) 6   
Chapter 3  Experimental Flow and Device Fabrication 8     
3-1  Pre-Etching 8
        3-2  Photo Enhanced Chemical Etching 8                            
        3-3  Device Fabrication 9 
3-3-1   Wafer Cleaning 9                                    
            3-3-2   Magnesium (Mg)-activation 10                                   
            3-3-3   Define mesa 10                              
            3-3-4   p-type GaN Surface Roughen 11                                    
            3-3-5   Deposit n-Metal 11                                   
            3-3-6   n-Ohmic Contact 12
            3-3-7   Deposition of TCL 12
            3-3-8   Deposit p-pad 13
            3-3-9   p-ohmic contact 13
Chapter 4  Results and Discussions 15      
4-1	Doping Level and Etching rate 16 
4-2	Surface Morphology after PEC Etching 17
4-3	Current-Voltage of Surface Roughened and Conventional LED 18
Chapter 5  Conclusions and Future Work 19
References 20
Figures

Figure Caption

Fig. 2-1	ICP-RIE 24 
Fig. 2-2	Micro Figure Measuring Instrument (α-step) 25
Fig.2-3	Atomic Force Microscopies (AFM) 26
Fig.2-4	Rapid Thermal Anneal (RTA) 27
Fig. 3-1	Traditional PEC Etching Scheme 28
Fig. 3-2	Photo Enhanced Chemical Etching       Apparatus Used in This Work 29       
Fig. 3-3	Light Output Intensity versus Wavelength 30
Fig. 4-1	Carrier Concentration versus Etching Depth 31
Fig. 4-2	Different Solutions 32
Fig. 4-3	Different Solutions (Continued) 33
Fig. 4-4	AFM picture of surface morphology after 2×1018 cm-3 n-GaN sample etched by 0.5M KOH solution for 10 Minutes 34  
Fig. 4-5	AFM picture of surface morphology after 2×1018 cm-3 n-GaN sample etched by 0.05M KOH solution for 10 Minutes 35 
Fig. 4-6	AFM picture of surface morphology after 2×1018 cm-3 n-GaN sample etched by 0.005M KOH solution for 10 Minutes 36  
Fig. 4-7	SEM picture of 2×1018 cm-3 n-GaN sample etched by 0.5M KOH solution for 5 Minutes 37
Fig. 4-8	SEM picture of 2×1018 cm-3 n-GaN sample etched by 0.5M KOH solution for 10 Minutes 38
Fig. 4-9	LED Structure 39
Fig. 4-10	 Forward Turn-On Voltage of Normal and  Etched LED 40                      
Fig. 4-11	 EL Spectrum of Normal and Etched LED 41
﻿	
                                    

References
[1]H. P Maruska, J. J Tietjen, “ The preparation and properties of vapor-deposited single-crystal-line GaN .” Appl. Phys. Lett , vol.15, p.327, 1969.

[2]R. Dingle, D. D Sell, S. E Stokowski, M. Ilegems, “Absorption, Reflectance, and Luminescence of GaN Epitaxial Layers.” Physical Review B, vol.4, p1211, 1971.

[3]J.I Pankove, J.E Berkeyheiser, E.A Miller, “Properties of Zn-doped GaN.” I. Photoluminescence J. Appl. Phys, vol.45, p.1280, 1974.

[4]M. E Lin, S. Strite, A. Agarwal, A. Salvador, G. L Zhou, N. Teraguchi, A. Rockett, and H. Morkoç, Moustakas, “GaN grown on hydrogen plasma cleaned 6H-SiC substrates.” Appl. Phys. Lett., vol.62, p.702, 1993.

[5]Shirakawa, Tsuguru, “Effect of defects on the degradation of ZnSe-based white LEDs.” Materials Science and Engineering: B. vol.91, p.470, 2002.

[6]H. Wenisch, M. Fehrer, M. Klude, K. Ohkawa, D. Hommel, “Internal
photoluminescence in ZnSe homoepitaxy and application in blue–green–orange
mixed-color light-emitting diodes.” Journal of Crystal Growth, vol.214, p.1075, 2000.

[7]K. Katayama, H. Matsubara, F. Nakanishi, T. Nakamura, H. Doi, A. Saegusa, T. Mitsui, T. Matsuoka, “ZnSe-based white LEDs.” Journal of Crystal Growth, vol.214, p.1064, 2000.

[8]D. Schmitz, E. Woelk, G. Strauch, M. Deschler, H. Jurgensen, “MOVPE growth of InGaN on sapphire using growth initiation cycles.” Materials Science and Engineering: B, vol.43, p.228, 1997.

[9]H. Morkoç, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns. “Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies.” J. Appl. Phys, vol.76, p.1363, 1994.

[10]S. Nakamura, T. Mukai, and M. Senoh. “High-brightness InGaN/AlGaN double-heterostructure blue-green-light-emitting diodes.” J. Appl. Phys, vol.76, p.8189, 1994.

[11]R. J. Molnar, R. Singh, and T. Moustakas, “Blue-violet light emitting gallium nitride p-n junctions grown by electron cyclotron resonance-assisted molecular beam epitaxy” Appl. Phys. Lett., vol.66, p.268, 1995.

[12]I. Adessida, A. Mahajan, E. Andideh, M. A. Kahn, D. T. Olson, and J. N. Kuznia, “Reactive ion etching of gallium nitride in silicon tetrachloride plasmas,” Appl. Phys. Lett., vol.63, p.2777, 1993.

[13]R. J. Shul, G. B. McClellan, S. A. Casalnuovo, and D. J. Rieger, “Inductively coupled plasma etching of GaN,” Appl. Phys. Lett., vol.69, p.1119, 1996.

[14]C. F. Zhu, W. K. Fong, B. H. Leung, C. C. Cheng, and C. Surya “Effects of Rapid Thermal Annealing on the Structural Properties of GaN Thin Films,” IEEE Trans. Electron Devices, vol.48, p.1225, 2001.

[15]S. J. Cai, Y. S. Tang, R. Li, Y. Y. Wei, L. Wong, Y. L. Chen, K. L. Wang, M. Chen, Y. F. Zhao, R. D. Schrimpf, J. C. Keay, and K. F. Galloway “Annealing Behavior of a Proton Irradiated AlxGa1-xN/GaN High Electron Mobility Transistor Grown by MBE,” IEEE Trans. Electron Devices, vol.47, p.304, 2000.

[16]M. E. Lin, Z. Ma, F. Y. Huang, Z. F. Fan, L. H. Allen, and H. Morkos, “Low resistance ohmic contacts on wide band-gap GaN.” Appl. Phys. Lett., vol.64, p.1003, 1994.

[17]P. J. Hartlieb, A. Roskowski, R. F. Davis, and R. J. Nemanich. “Chemical, electrical, and structural properties of Ni/Au contacts on chemical vapor cleaned p-type GaN.” J. Appl. Phys, vol.91, p.9151, 2002.

[18]R.W. Chuang, A. Q. Zou, and H.P. Lee, Z.J. Dong, “Contact Resistance of InGaN/GaN Light Emitting Diodes Grown on the Production Model Multi-Wafer MOVPE Reactor.” MRS Internet Journal Nitride Semiconductor Research. 4S1, G6.42, 1999.

[19]T. Mori, T. Kozawa, T. Ohwaki, and Y. Taga, “Schottky barriers and contact resistances on p-type GaN.” Appl. Phys. Lett., vol.69, p.3537, 1996.

[20]Chen-Fu Chu, C. C. Yu, Y. K. Wang, J. Y. Tsai, F. I. Lai, and S. C. Wang, “Low-resistance ohmic contacts on p-type GaN using Ni/Pd/Au metallization” Appl. Phys. Lett., vol.77, p.3423, 2000.

[21]W. Götz, M. Johnson, and D. P. Bour, “Deep level defects in Mg-doped,p-type GaN grown by metalorganic chemical vapor deposition,” Appl. Phys. Lett, vol.68, p.3470, 1996.

[22]F. A. Reboredo and S. T. Pantelides, “Novel defect complex and their role in the p-type doping of GaN,” Phys. Rev. Lett, vol.82, p.1887, 1994.

[23]J. Neugebauer and C. G. Van de Walle, “Hydrogen in GaN: Novel aspects of a common impurity,” Phys. Rev. Lett., vol.75, p.4452, 1995.

[24]M. Miyachi, T. Tanaka, Y. Kimura, and H. Ota, “The activation of Mg in GaN byannealing with minority-carrier injection,” Appl. Phys. Lett, vol.72, p.1101, 1998 .

[25]B. A. Hull, S. E. Mohney, H. S. Venugoplan, and J. C. Ramer, “Influence of oxygen on the activation of p-type GaN,” Appl. Phys. Lett., vol.76, p.2271, 2000.

[26]S. H. Chung, M. Lachab, T. Wang, Y. Lacroix, D. Basak, Q. Fareed, Kawakami, K. Nishino, and S. Sakai, “Effect of oxygen on the activation of Mg acceptor in GaN epilayers grown by metalorganic chemical vapor deposition. ” Jpn. J. Appl. Phys., vol.39, p.4749, 2000.

[27]T. C. Wen, S. C. Lee, T. Y. Chen, S. H. Chan, and J. S. Tsang, “Activation of p-type GaN in a pure oxygen ambient,” Jpn. J. Appl. Phys., vol.40, p.495, 2001.

[28]Y. Koide, T. Maeda, T. Kawakami, S. Fujita, T. Uemura, N. Shibata, and M. Murakami, “Effects of annealing in an oxygen ambient on electrical properties of ohmic contacts to p-type GaN,” J. Electron. Mater, vol.28, p.341, 1999.

[29]J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, K. K. Shih, L. C. Chen, F. R.Chen,and J. J. Kai, “Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films,” J. Appl. Phys., vol.86, p.491, 1998.

[30]L. C. Chen, F. R. Chen, J. J. Kai, J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, and K. K. Shih, “Microstructural investigation of oxidized Ni/Au ohmic contact to p-type GaN,” J. Appl. Phys., vol.86, p.3826, 1999

[31]J. K. Sheu, J. M. Tsai, S. C. Shei, W. C. Lai, T. C. Wen, C. H. Kou, Y. K. Su, S. J. Chang, and G. C. Chi, “Low-operation voltage of InGaN/GaN light-emitting diodes with Si-doped In Ga N/GaN short-period superlattice tunneling contact layer,” IEEE Electron. Dev. Lett., vol.22, p.460, 2001.

[32]K. Kumakura and N. Kobayashi, “Increased electrical actitivity of InGaN/GaN superlattices,” Jpn. J. Appl. Phys., vol.38, p.449, 1999.

[33]P. Kozodoy, M. Hansen, S. P. DenBaars, and U. K. Mishra, “Enhanced Mg doping efficiency in Al0.2Ga0.8N/GaN superlattices,” Appl. Phys. Lett., vol.74, p.3681, 1999.

[34]R. Dingle, H. L. Stormer, A. C. Gossard, and W. Wiegmann, “Electron mobilities in modulation-doped semiconductor heterojunction superlattices,” Appl. Phys. Lett., vol.33, p.665, 1978.

[35]I. D. Goepfert et al., “Experimental and theoretical study of acceptor AlGaN/GaN superlattices,” J. Appl. Phys., vol.88, p.2030, 2000.

[36]I. D. Goepfert et al., “Demonstration of efficient p-type doping in AlGaN/GaN superlattice structures,” Electron Lett., vol.35, p.1109, 1999.

[37]M. E. Lin, Z. Ma. F. Y. Huang, Z. F. Fan, L. H. Allen, and H. Morkoc, “Low resistance ohmic contacts on wide band-gap GaN.” Appl. Phys. Lett., vol.64, p.1003, 1994

校內：2055-07-19公開
校外：2056-07-19公開電子論文尚未授權公開，紙本請查館藏目錄

簡易檢索 / 詳目顯示

相關論文