簡易檢索 / 詳目顯示

回結果列表
研究生： 屈岳杰
Chiu, Yueh-Jye
論文名稱： 氮化鎵系列之歐姆接觸與其發光二極體光電特性之研究
The optoelectronic characteristics study of nitride based to ohmic contact and LEDs
指導教授： 莊文魁
Chuang, Ricky Wenkuei
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： 2005
畢業學年度： 93
語文別： 英文
論文頁數： 71
中文關鍵詞： 超晶格 、歐姆接觸 、氮化鎵
外文關鍵詞： superlattice, ohmic contact, GaN
相關次數： 點閱：45  下載：1 
分享至:
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

    • 論文主題主要是研究三五材料中p-type GaN 的歐姆接觸特性及 SPS LED的半透明導電膜上的應用，由於p-type GaN 能帶間距(Eg)與電子親和力(χ)相當大以至於無法找到適當的單一金屬的功函數使其接觸後形成歐姆特性,另一方面材料本身受體(acceptor)濃度難以活化增加歐姆接觸的難度，其材料濃度多半低於1018cm-3以下，導致歐姆特性比其他材料還差，如矽(Si)和砷化鎵(GaAs)等。市面上的接觸電阻大約在10-2~10-4Ω-cm-2之間，這對於小接觸面積及低供給電壓會產生相當大的電壓損耗，這是我們所不樂見的。基於以上因素，吾人利用兩種不同金屬組合來提升複合金屬的功函數使其接觸後形成歐姆特性，另外適當的表面處理來增加材料表面受體濃度以及清潔表面，然後找出最佳回火溫度及時間以得到最低歐姆接觸電阻值。PL 量測為討論表面處理前後波形的改變。
    除了量得I-V以外並提出適當的數學模型來描述電流傳輸的機制，最後利用材料分析儀器(SIMS)來分析金屬與材料界面間的元素分佈並找出各元素分佈與接觸電阻的關係。
    實驗的第二部份為應用於SPS LED的半透明金屬層(TCL)上，以不同的金屬組合來分析各元件的光電特性並討論電流擴散效應，再藉由AFM分析來找出元件特性好壞的原因所在。

    In recent years,GaN material is applied to optoelectronic devices,such as photodetectors, light-emitting diodes and laser diodes. But the p-type GaN is more difficult to find out that the specific contact resistivity is below 10-5 Ω-cm2 than n-type. Good ohmic contact is important for devices performance. In addition, there are two key obstacles for ohmic contact to p-type GaN. (i) It is a difficulty in growing heavily doped p-type GaN(>1018cm-3) and (ii) it is the absence of appropriate metals which have a work function higher than that of p-type GaN(6.5eV). Based on above, many groups have attemped to achieve low-resistance ohmic contact on p-type GaN.
    Secondly, the metal layer(semi-transparent) of LEDs is a key point to affect the current spreading. Uniform current distribution is needed for better devices performance than none and enhanced light output intensity.
    In our experiments, we try to find out good ohmic contact by different metal combinations, such as Ir/Pr, Ir/Nb, Pt/Ir, Ni/Au Ni/Nb and Ir/Au. According to different surface treatment and annealing time, measuring I-V characteristic (including in varied temperature ambiance) to computer experimently specific contact resistivity(ρc) and the Richardson constant(A*).
    From theoretically I-V property, we calculate effective barrier height(φb) and ideality factor(n). We also have analyzed by SIMS. Finally, we attempt to deposit different metal contact layer e.g. Ir/Au, Ir/Nb, Ir/Ni, Ir/Ru, Ni/Au, and Ni/Nb, on the top of SPS LEDs and compare with optical and electrical properties, respectively.

    Contents 　 page 中文摘要................................................................ i Abstract. ...............................................................iii 誌謝.................................................................... v Contents................................................................vii Chapter1 Introduction.......................................... 1 1-1 The background of ohmic contact to p-GaN.............. 1 1-2 Some effects influence ohmic contact to p-GaN......... 2 1-2-1 Metal work function................................... 3 1-2-2 Properties of Mg acceptor in GaN...................... 5 1-2-3 Surface treatment..................................... 7 1-3 Current spreading.....................................12 Chapter2 Theory................................................15 2-1 Schottky barrier......................................15 2-2 Nonideal effects on the barrier height................17 2-2-1 Image-force lowing the barrier........................17 2-2-2 The effect of surface states..........................19 2-2-3 The effects of insulating layer.......................20 2-3 Electrons transport...................................21 2-3-1 The thermionic-emission theory........................23 2-4 Specific contact resistivity..........................25 2-5 The measurement of CTLM...............................26 2-6 Lateral current transport path on LEDs................27 Chapter3 Experiments...........................................32 3-1 Instruments...........................................32 3-1-1 E-beam evaporator.....................................32 3-1-2 Photoluminescence.....................................33 3-1-3 Secondary ion mass spectrometry.......................35 3-1-4 Atomic Force Microscope...............................36 3-2 Experimental process..................................37 3-2-1 Varied contacts to p-GaN..............................37 3-2-2 Spreading layers on SPS LEDs..........................39 3-3 Experimental results..................................41 Chapter4 Discussions...........................................54 4-1 Ohmic contact to p-GaN................................54 4-2 SPS structure of LEDs.................................58 Chapter5 Conclusions...........................................65 Chapter6 Future Works..........................................67 References 68

    References
    [1]S. Nakamura, T. Mukai, and M. Senoh, Appl. Phys. Lett. vol.64, pp.1687, 1994.
    [2]Y. Z. Chiou, Y. K. Su, S. J. Chang, J. Gong, Y. C. Lin, S. H. Liu, and C. S. Chang, IEEE J. Quantum Electron. vol.39, pp.681-685, May 2003.
    [3] Y. K. Su, S. J. Chang, C. H. Chen, J. F. Chen, G. C. Chi, J. K. Sheu, W. C. Lai, and J. M. Tsai, IEEE Sensors J. vol.2, pp.366-371, Apr. 2002.
    [4]S. Nakamura, S. Pearton, G. Fasol, The Blue Laser Diode: The Complete Story, 2nd , Springer, New York, 1997
    [5]H. Ishikawa, S. Kobayashi, and Y. Koide, J. Appl. Phys. vol.81, pp.1315, 1997
    [6]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, J. Appl. Phys. vol.86, pp.4491, 1999
    [7]史光國,　現代半導體發光及雷射二極體材料技術,　全華
    [8]史光國,　現代半導體發光及雷射二極體材料技術-進階篇,　全華
    [9]S.H. Liu, J.M. Hwang, Z.H. Hwang, W.H. Hung, H.L. Hwang, Applied Surface Science 212–213 (2003) 907–911
    [10]June O Song and Dong-Seok Leem, Joon Seop Kwak, O. H. Nam, and Y. Park, Tae-Yeon Seong, Appl. Phys. vol.83, pp.2372, 2003
    [11]Ho Won Jang and Jong-Lam Lee, J. Appl. Phys. vol. 93, pp.5146, 2001
    [12]DAE-WOO KIM, JUN CHEOL BAE, WOO JIN KIM, HONG KOO BAIK, JAE-MIN MYOUNG, and SUNG-MAN LEE, Pd-Based Contact to p-GaN by Surface Treatment Journal of ELECTRONIC MATERIALS, Vol. 30, No. 3, 2001
    [13]T. Mori, T. Kozawa, T. Ohwaki, Y. Taga, S. Nagai, S. Yamasaki, S. Asami, N. Shibata, and M. Koike, Appl. Phys. Lett. vol.69, pp.3537, 1996
    [14]H. Obloh, K. H. Bachem, U. Kaufmann, M. Kunzer, M. Maier, and A. Ramakrishnan, J. Crystal Growth 195(1998) 270-273
    [15]S. Nakamura, S. Pearton, and G. Fasol, The Blue Laser Diode, Springer, New York, 2000
    [16]C. H. Kuo, S. J. Chang, Y. K. Su, L. W. Wu, J. K. Sheu, C. H. Chen, and G. C. Chi, Jpn. J. Appl. Phys. vol. 41 (2002) pp. L112-L114
    [17]T. C. Wen, S. C. Lee, W.-I Lee, T. Y. Chen, S. H. Chan, and J. S. Tsang, Jpn. J. Appl. Phys. vol. 40 (2001) pp. L495-L497
    [18]S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin and J. C. Ke, IEEE Journal of Quantum Electronics, vol.39 no.11 November 2003 pp.1439
    [19]J. K. Kim, K. J. Kim, B. Kim, J. N. Kim, J. S. Kwak, Y. J. Park, and J. L. Lee, J. of Electronic Materials, vol. 30, no. 3, pp. 129, 2001
    [20]D. C. Look, D. C. Reynolds, J. W. Hemsky, J. R. Sizelove, R. L. Jones, and R. J. Molnar, Phys. Review Lett. Vol. 79, no. 12, pp. 2273, Sep. 1997
    [21] J. K. Kim, C. C. Kim, T. S. Cho, J. H. Je, J. S. Kwak, Y. J. Park, and J. L. Lee, J. of Electronic Materials, vol. 30, no. 3, pp. 170, 2001
    [22]Y. J. Lin, Z. L. Wang, and H. C. Cang, Appl. Phys. Lett. vol.81, pp.5183, 2002　
    [23]J. K. Kim, J. L. Lee, J. W. Lee, Y. J. Park. T. Kim, J. Vac. Sci. Technol. B 17(2), pp. 497, 1999
    [24]J. Sun, K. A. Rickert, J. M. Redwing, A. B. Ellis, F. J. Himpsel, and T. F. Kuech, Appl. Phys. Lett. vol.76, pp.415, 2000
    [25]J. L. Lee, J. K. Kim, J. W. Lee, Y. J. Park. T. Kim, Solid-State Electronics 43(1999) 435-438
    [26]E.H. Rhoderick and R.H. William, Metal-Semiconductor Contacts, CLAREDON PRESS, OXFORD, 2nd, 1988
    [27]曾威揚, The Effect of Surface Treatment on p-type GaN Ohmic contact, 2003
    [28]Donald A. Neamen, Semiconductor Physics & Devices, McGraw-Hill, 3rd
    [29]Dieter K. Schroder, Semiconductor material and device characterization, Wiley, 2nd
    [30]施敏,　半導體元件物理與製作技術,　國立交通大學出版社, 2nd
    [31]H. Kim, S.J. Park, H. Hwang and N. M. Park, Appl. Phys. Lett. vol.81, pp.1326, 2002
    [32]Hong Xiao, Introduction to Semiconductor Manufacturing Technology
    [33]凌永健,　二次離子質譜儀,　科儀新知, 11(2), 1989
    [34]S. R. Jeon, Y. H. Song, H. J. Jang, and G. M. Yang, Appl. Phys. Lett. vol.78, pp.3265, 2001
    [35]C. H. Liu, Y. K. Su, L. W. Wu, S. J. Chang, and R. W. Chuang, Semicond. Sci. Technol. 18(2003) 545-548
    [36] 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, IEEE ELECTRON DEVICE LETTERS, VOL. 22, NO. 10, OCTOBER 2001
    [37] C. H. Kuo, S. J. Chang, Y. K. Su, L. W. Wu, J. F. Chen, J. K. Sheu,
    and J. M. Tsai, IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 50, NO. 2, FEBRUARY 2003

    下載圖示 校內：2007-06-27公開
    校外：2008-06-27公開
    QR CODE