臺灣博碩士論文加值系統

本論文主要研究氮化鎵材料與元件製程相關之技術，其中包括P型歐姆接觸特性、發光二極體的P型歐姆接觸及利用準分子雷射剝離氮化鎵發光二極體技術。在P型歐姆接觸方面，我們發現藉由使用P型氮化鎵材料熱退火條件為氮氣環境中800℃加蓋(with cap)，再退火30分鐘，提高了霍爾濃度並改善了材料品質。將此再次熱退火條件結合P型歐姆接觸-Ni/Pd/Au金屬結構在氧氣環境550℃，5分鐘的金屬退火處理下，可得到良好的歐姆接觸並得到低特性電阻值約為3.9×10-4 Ω-cm2 ，由SIMS分析結果來看，低阻值的產生可能與退火過程中在氮化鎵介面產生跟NiO及Au-Pd-Ga合金有關。
在發光二極體P型歐姆接觸方面，我們以同樣Ni/Pd/Au金屬結構為P型歐姆接觸並調整各種不同的製程及熱退火條件，藉以建立氮化鎵發光二極體最佳操作性能的製程方式。比較結果發現以氮氣環境中800℃加蓋(with cap)，再退火15分鐘，並配合以Ti/Al/Ni/Au為n型金屬電極所製作之發光二極體可達順向導通電壓為3伏特，阻值為24.5Ω的最佳電性量測結果。
在雷射剝離技術研究上，我們成功地利用準分子雷射技術及二次轉移過程將氧化鋁基板去除，並將氮化鎵發光二極體黏合(bonding)到銅基板上。由I-V量測結果來看，在銅基板上的發光二極體其阻值比氧化鋁基板上的低。而由電激發光譜發現，經過雷射剝離技術的發光二極體，其波長有些微的紅移現象。

We study the process techniques of GaN material and GaN-based device including ohmic contact on p-GaN, p-type ohmic contact on GaN LED,and excimer laser lift-off of GaN-based LED. For p-GaN Ohmic contact, by re-annealing the in-situ p-GaN sample in the external furnace under 800℃ for 30 minutes with cap in N2-ambient, the hole carrier concentration was increased and the material quality was also improved. We obtained good p-type ohmic characteristic with a specific contact resistivity as low as 3.9×10-4 Ω-cm2 by using re-annealing samples combined with the Ni/Pd/Au metallization scheme followed by thermal treatment in oxygen ambient at 550℃ for 5 minutes. From the SIMS measurement, we found the low specific resistance maybe related to the formation of NiO and Au-Pd-Ga alloy on surface of GaN.
For p-type ohmic contact on GaN-based LEDs, we applied the same p-type ohmic contact(Ni/Pd/Au) and re-annealing condition on GaN-based LED, and obtained an optimum process condition for LED sample by re-annealing the sample in the external furnace under 800℃ for 15 minutes with cap in N2-ambient. With the Ti/Al/Ni/Au metallization scheme as n-type contact, the LEDs showed low turn-on voltage of 3V and low resistance of 24.5Ω.
In the development of excimer laser lift-off technique, we successfully separated GaN based LED from sapphire substrate using excimer laser and transferred on the Cu substrate by laser lift-off (LLO) technique and two-step transformation process. From the I-V curve, we found the LED on Cu substrate had smaller resistance than LED on Sapphire substrate. The LLO-LED electroluminescence(EL) spectrum showed the peak wavelength is slightly red-shifted from the LED on sapphire.

目 錄
頁數
中文摘要 ……...…….……………………………....…………………..i
英文摘要….………………………………………...…….………....ii
誌謝……..……………………………………………….…….…….iii
目錄..……………….……………………………………………………iv
圖表目錄..……………………………………………….……….…vii
第一章 緒論………………………………..…………………………………………1
1.1 P型氮化鎵歐姆接觸..…………………………………………………………….1
1.2 氮化鎵雷射剝離技術..…………………………………………………………....3
第二章 P型氮化鎵歐姆接觸及再次熱退火條件之研究……………...……………5
2.1 引言………………………………………………………………………………5
2.2 金屬與半導體接觸原理…………………………………………………………6
2.2.1 半導體接觸的理想模型……………………………………………………..6
2.2.2 薄膜擴散的理論模型………………………………………………………..8
2.2.3 金屬與半導體之間的電流傳輸……………………………………………10
2.2.4 P型半導體的歐姆接觸……………....…………………………………...11
2.3 熱處理效應理論………………………………………………………………..12
2.3.1退火三階段………………………………………………………………….12
2.3.2退火溫度與時間…………………………………………………………….12
2.4金屬與半導體接觸特性量測方法………………………………………………14
2.4.1霍爾載子濃度量測…………………………………………………………14
2.4.2雙晶X-ray繞射分析……………………………………………………….15
2.4.3光激發光譜分析……………………………………………………………16
2.4.4 Circular Transfer Length Method………………………………………… ..17
2.4.5 二次離子質譜分析………………………………………………………...20
2.5 實驗方法與步驟………………………………………………………………..23
2.5.1 MOCVD成長氮化鎵薄膜………………………………………………….23
2.5.2 再次熱退火試片製備……………………………………………………....24
2.5.3 金屬接觸製作………………………………………………………………25
2.5.4 歐姆接觸電性量測與材料分析……………………………………………27
2.6 實驗結果與討論………………………………………………………………...29
2.6.1再次熱退火處理試片材料特性與分析…………………………………….29
2.6.2 I-V電性量測結果(CTLM)………………………………………………….31
2.6.3 P型氮化鎵金屬歐姆接觸材料分析………………………………………..33
第三章 P型金屬歐姆接觸在氮化鎵發光二極體上的應用……………………….37
3.1 引言……………………………………………………………………………...37
3.2 氮化鎵發光二極體原理………………………………………………………...37
3.2.1 發光二極體簡述……………………………………………………………37
3.2.2 發光二極體原理……………………………………………………………38
3.3實驗方法與步驟…………………………………………………………………41
3.3.1試片結構…………………………………………………………………….41
3.3.2氮化鎵發光二極體再次熱退火試片準備………………………………….41
3.3.3氮化鎵發光二極體元件製程步驟………………………………………….42
3.3.4 量測實驗裝置………………………………………………………………50
3.4 實驗結果與討論………………………………………………………………...52
3.4.1 I-V curve電性量測…………………………………………………………52
3.4.2 發光二極體光譜分析………………………………………………………56
第四章 準分子雷射剝離技術之研究………………………………………………62
4.1 引言…..…………………………………………………………………………..62
4.1.1 雷射蝕刻技術……………………………………………………………..62
4.1.2 雷射剝離技術……………………………………………………………..63
4.2 原理……………………………………………………………………………...64
4.2.1準分子雷射………………………………………………………………….64
4.2.2 熱模擬分析…………………………………………………………………65
4.2.3 雷射剝離技術之原理………………………………………………………67
4.3 實驗方法及步驟………………………………………………………………...68
4.3.1準分子雷射剝離實驗架構………………………………………………….68
4.3.2 試片準備……………………………………………………………………68
4.3.3 雷射剝離及二次轉移之方法與步驟………………………………………69
4.4 實驗結果與討論………………………………………………………………...72
第五章 結論及展望…………………………………………………………………75
參考資料……………………………………………………………………………..77

參考資料
1. S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, Jpn. J. Appl. Phys., Part 2(34), L797 (1995).
2. S. Nakamura, T. Mokia, and M. Senoh, Appl. Phys. Lett. 64, 1689 (1994).
3. S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Mat-sushita, Y. Sugimoto, and H. Kiyodo, Appl. Phys. Lett. 70, 868 (1996).
4. M. A. Khan, A. R. Bhattarai, J. N. Kuznia, and D. T. Oslon, Appl. Phys Lett. 62, 1786 (1993).
5. M. A. Khan, J. N. Kuznia, D. T. Olson, J. M. Van Hove, M. Blasingame, and L. F. Reitz, Appl. Phys. Lett. 63,1(1993).
6. J. S. Foresi and T. D. Moustakas, Appl. Phys. Lett. 62, 2859 (1993).
7. M. E. Lin, Z. Ma, F. Y. Huang, Z. F. Fan, L. H. Allen, and H. Morkoc¸, Appl. Phys. Lett. 64, 1003 (1994).
8. Z. Fan, S. Mohammad, and W. Kim, Appl. Phys. Lett. 68, 1672 (1996).
9. S. Ruvimov, Z. Liliental-Weber, and J. Washbum, Appl. Phys. Lett. 69,1556 (1996).
10. A. T. Ping, M. Asif Khan, and I. Adesida, J. Electron. Mater. 25, 819(1996).
11. W. Gotz, N. M. Johnson, J. Walker, D. P. Bour, and R. A. Street, Appl. Phys. Lett. 68,667(1996).
12. Strite S and Morkoc H, J. Vac.Sci. Technol. B 10,1237(1992).
13. Robin M, Newman N, Chin J S, Fu T C and Ross J T, Appl. Phys. Lett. 64,64(1994)
14. T. Mori, T. Kozawa, T. Ohwaki, Y. Taga, S. Nagai, S. Yamasaki, S. Asami, N. Shibata, and M. Koike, Appl. Phys. Lett. 69 3537(1996).
15. L. L. Smith, R. F. Davis, M. J. Kim, R. W. Carpenter, and Y. Huang, L. L. Smith, R. F. Davis, M. J. Kim, R. W. Carpenter, and Y. Huang,
16. K. V. Vassilevski, M. G. Rastegaeva, A. I. Babanin, I. P. Nikitina, and V. A. Dmitriev, MRS Internet J. Nidride Semicond. Res.1,38(1996).
17. Y. Yamaoka, Y. Kaneko, S. Nakagawa, and N. Yamada, Proceeding of Y. Yamaoka, Y. Kaneko, S. Nakagawa, and N. Yamada, Proceeding of Tokushima Japan,27-31 October 1997, p1-19.
18. D. J. King, L. Zhang, J. C. Ramer, S. D. Hersee, and L. F. Lester, Mater. Res. Soc. Symp. Proc. 468, 421(1997)
19. T. Kim, J. Khim, S.Chae, and T. Kim, Mater. Res. Soc. Symp Proc.468 , 427(1997)
20. T. Kim, M. C. Yoo, and T. Kim, Mater. Res Soc. Symp. Proc.449,1061(1997)
21. H. Ishikawa, S. Kobayashi, Y. Koide, S. Yanmasaki, S. Nagai, J. Umezaki, M. Koike, and M. Murakami, J. Appl. Phys. 81,1315(1997)
22. J. T. Trexler, S. J. Pearton, P. H. Holloway, M. G. Mier, K. R. Evans, and R. F. Karlicek, Mater. Res. Soc. Symp. Proc. 449,1091(1997)
23. T. Kim, J. Khim, S.Chae, and T. Kim, Mater. Res. Soc. Symp. Proc.468 , 427(1997)
24. J. K. Kim, J. L. Lee, J. W. Lee, H. E. Shin, Y. J. Park, and T. Kim, Appl. Phys. Lett. 73,2953(1998)
25. J. —S. Jang, I.-S. Chang, T.-Y. Seong, S.Lee, and S.-J. Park, proceeding of the Second International Symposium on Blue Laser and Light Emitting Diode, Chiba, Japan, 29 September-2 October 1998, p. Tu-P33
26. L. Zhou, W. Lanford, A. T. Ping, and I. Adesida, Appl. Phys. Lett.76 3451(2000).
27. J. —S. Jang, S.-J. Park, and T.-Y. Seong, Appl. Phys. Lett.76 2898(2000)
28. C. R. Lee, J.Y. Leem and B. G. Ahn Journal of Crystal Growth 216, 62 (2000).
29. 賴芳儀，國立交通大學光電工程研究所，碩士論文(2000).
30. C. F. Chu, C. C. Yu, Y. K. Wang, J. Y. Tsai, F. I. Lai, and S. C. Wang, Appl. Phys.
Lett. 77, 3423 (2000).
31. S.D. Lester, F.A. Ponce, M.G. Craford, and D.A. Steigerwald, Appl. Phys. Lett. 66,1249 (1996).
32. A.T. Ping, Q. Chen, J.W. Yang, M.A. Khan, I. Adesida, IEEE Electron Device Letters 19, 54 (1998).
33. D.L. Barton, M. Osinski, C.J. Helms, N.H. Berg, B.S. Phillips, SPIE-Int. Soc. Opt. Eng 2694, 64 (1996).
34. J. Haisma, G.A.C.M Spierings, U.K.B. Biermann, and J.A. Pals, Jpn. J. Appl. Phys. 28, 1426 (1989).
35. T. Detchprohm, H. Amano, K. Hiramatsu, and I. Akasaki, J. Cryst. Growth 128, 384 (1993).
36. W.S. Wong, T. Sands, and N.W. Cheung, Appl. Phys. Lett. 72, 599 (1998).
37. M.K. Kelly, O. Ambacher, R. Dimitrov, R. Handschuh, and M. Stutzmann, Phys. Stat. Sol. (A) 159, R3 (1997).
38. W. S. Wang, L. F. Schloss, G. S. Sudhir, B. P. Linder, K. M. Yu, E. R. Weber, T Sands, and N. W. Cheung, Master. Res. Soc. Symp. Proc. 449, 1011(1997).
39. W. S. Wang, and T. Sands, compound semiconductor 5(9), 55(1999).D. J. King, L. Zhang, J. C. Ramer, S. D. Hersee, and L. F. Lester, Mater. Res. Soc. Symp. Proc. 468, 421 (1997).
40. W. S. Wang, M. Kneissl, P. Mei, A. W. Treat, M. Teepe, and N. M. Johnson, Jpn. J. Appl. Phys. Part2, 12A,L1203(2000).
41. M. J. Howes and D. V. Morgan “Gallium Arsenide” chapter 6 (1986).
42. Hadis Morkoc “Nitride Semiconductors and Devices” p196-197.
43. J. M. Poate, K. N. Tu and J. W. Mayer “Thin films - interdiffusion and reactions” (1978) p310.
44. W. Shockley in A. Goetzberger and R. M. Scarlett, “Reserch and Investigation of Inverse Epitaxial UHF Power Transistor,” ReP. No. AFAL-TDR-64-207, Air Force Avionics Lab., Wright-Patterson Air Force Base, OH, Sept. 1964.
45. G. S. Marlow and M. B. Das,Sol. Stat. Electro. 25,91(1982)
46. L. F. Lester, J. M. Brown, J. C. Ramer, L. Zhang, and S. D. Hersee, Appl. Phys. Lett. 69, 2737(1996).
47. P. Williams and J. E. Baker, Nucl. Instrum. Methods, 182/183,15(1981).
48. K. Wittmaack, Vacuum 34,119(1984).
49. D. C. Look, D. C. Reynold, U. W. Hemsky, J. R. Sizelove, R. L. Jones and R. J. Molnar, Phys. Rev. Lett. 79, 2273(1997).
50. J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, and K. K. Shin., J. Appl. Phys. 86,4491(1999).
51. J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, and K. K. Shin., Appl. Phys. Lett. 74,1275(1999).
52. N. Birks and G. H. Meier, Introduction to High Temperature Oxideation of Metals, Ch 3(1982).
53. Hadis Morkoc “Nitride Semiconductors and Devices” p303
54. Z. Fan, S. N. Mohammad, W. kim, O. Aktas, A. E. Botchkarev, and H. Morkoc, Appl. Phys. Lett. 68, 1672(1996).
55. D. Behr, J. Wagner, A. Ramakrishnan, H. Obloh, and K. H. Bachem, Appl. Phys. Lett. 73, 241(1998).
56. Y. Narukawa, Y. Kawakami, Sg. Fujita, and S. Nakamura, Phys. Rev. B 59,10283(1999).
57. T. Takeuchi, S. Sota, M. Katsuragawa, M. Komori, H. Takeuchi, H. Amano, and I. Akasaki, Jap.J.Appl.Phys.36,L382,(1997).
58. C. F. Chu, C. K. Lee, C. C. Yu, Y. K. Wang, J. Y. Tasi, C. R. Yang* and S. C. Wang, Proceeding of International Workshop of Nitride in Japan (2000).
59. Integration of GaN Thin Film with Dissimilar Substrate Materials by Wafer Bonding and Laser Lift-off， W. S. Wong， Engineering Material Science of the UNIVERSITY OF CALIFORNIA,BERKELEY (1999).
60. R. Groh, G. Gerey, L. Bartha and J. I. Pankove, Phys. Stat. Sol. A 26,353(1974).