本論文針對氮化鋁鎵/氮化鎵系列PIN紫外光偵測器元件做相關之研究與製作，包括成長具有不同吸收層p-i-n結構與具有p+-GaN/n+-GaN穿隧接面n-i-p結構。
在具有不同吸收層p-i-n結構中，由於傳統氮化鎵吸收層光偵測器在吸收層厚度的控制上，受到載子漂移速度與RC頻寬限制，另外由於載子漂移累積，產生嚴重的空間電荷遮蔽效應，造成頻寬限制與輸出功率衰退的缺點。有鑑於此，我們利用低溫成長氮化鎵與氮化鎵結合構成吸收層，與傳統氮化鎵吸收層作比較。由於低溫成長氮化鎵結晶品質很差，內部存在許多缺陷，載子於傳輸時將被此缺陷捕捉，利用此特性，我們可將元件的響應速度從原本載子漂移限制轉變成以載子生命期為主導因素，加快元件的操作速度，改善了傳統氮化鎵吸收層所面臨的問題。
在具有p+-GaN/n+-GaN穿隧接面n-i-p結構中，我們利用反向成長n-i-p結構，減少一道p型歐姆接觸金屬製程，使得光偵測器的製程簡化。另外，n-i-p結構光偵測器的光電特性並不比傳統p-i-n結構差，這對大量生產與人力成本消耗的高科技光電半導體產業而言，將是可以繼續研發改進的光偵測器元件之一。

This thesis aims at fabricating and characterizing of AlGaN/GaN PIN ultraviolet photodetectors (PDs). We have fabricated two kinds of PDs, including p-i-n structures with different absorption layers and n-i-p structures with buried p+-GaN/n+-GaN tunneling junction.
In the p-i-n PDs, PDs with low-temperature-growth GaN as absorption layers are systematically compared with the traditional PDs. There have some fundamental limits of traditional PD. For instances, the absorption thickness is limited by the carrier-drift-velocity, RC-constant, and space-charge- shielding effect, and results in restriction on bandwidth and output power. To improve the performance regarding to above-mentioned specifications, we attempt to insert a LT-GaN film as a part of the absorption layer. However, owing to the inferior quality of LT-GaN film, photo-generated carriers will be trapped by native defects. Therefore, the improvement is limited.
In the n-i-p PDs, the p+/n+ tunneling junction, with a low-resistivity n++-In0.3Ga0.7N layer associated with a p+-GaN layer deposited on an n-type GaN bottom contact layer, allows the anode electrode contact to be formed directly on the n-type GaN bottom contact layer. When a bias is applied to the device with the aforesaid inverted structure, the tunneling junction will behave like an “Ohmic contact”. Accordingly, an inverted p-i-n UV PD can operate like a conventional device. Owing to the inverted structure, we can performe both p-ohmic contact and n-ohmic contact in a single metal deposition procedure and thereby reduce the production cost of the PDs. Besides, the n-i-p structure also has acceptable performances compared with conventional p-i-n structures. Results, including I-V characteristics and spectral responsivity, are addressed in this thesis.

[1] J. I. Pankove, “Perspective on gallium nitride,” in Proc. Mater. Res. Soc., vol. 162, May 1990, pp. 515-519.
[2] M. S. Shur, “GaN Based Transistors for High Power Applications”,
Solid-State Electronics, Vol. 42, pp. 2131 (1998)
[3] M. A. Khan, J. N. Kuznia, D. T. Olson, W. J. Schaff, J. W. Burm,
and M. S. Shur, “Microwave performance of a 0.25 μm gate AlGaN/
GaN heterostructure field effect transistor”, Appl. Phys. Lett. Vol.
65, pp. 1121 (1994)
[4] F. Ren, C. R. Abernathy, J. M. Van Hove, P. P. Chow, R. Hickman, J.
J. Klaasen, R. F. Kopf, H. Cho, K. B. Jung, J. R. La Roche, R. G.
Wilson, J. Han, R. J. Shul, A. G. Baca, and S. J. Pearton, “300°C
GaN/AlGaN Heterojunction Bipolar Transistor”, MRS Internet J.
Nitride Semicond. Res. Vol. 3, 41 (1998)
[5] M. A. Khan, J. N. Kuznia, A. R. Bhattarai, and D. T. Oslon, “Metal
semiconductor field effect transistor based on single crystal GaN”,
Appl. Phys. Lett. Vol. 62, pp. 1786 (1993)
[6] G. S. Nakamura, “InGaN-based violet laser diodes”, Semicond. Sci.
Technol. Vol. 14, pp. R27 (1999)
[7] M. A. Khan, J. N. Kuznia, D. T. Olson, M. Blasingame, and A. R.
Bhattarai, “Schottky barrier photodetector based on Mg-doped
p-type GaN films”, Appl. Phys. Lett. Vol. 63, pp. 2455 (1993)
[8] E. Monroy, T. Palacios, O. Hainaut, F. Omnes, F. Celle, J. F.
Hochedez, “Assessment of GaN metal-semiconductor-metal
photodiodes for high-energy ultraviolet photodetection“, Appl. Phys.
Lett. Vol. 80, pp. 3198 (2000)
[9] M. Asif Khan, J. N. Kuznia, D. T. Olson, J. M. Van hove, M. Blasingame,
L. F. Reitz, “High-responsivity photoconductive ultraviolet sensors based
on insulating single-crystal GaN epilayers”, Appl. Phys. Lett. Vol. 60, pp.
2917 (1992)
[10] E. Monroy, E. Muñoz, F. J. Sánchez, F. Calle, E. Calleja, B. Beaumout,
P. Gibart, J. A. Muñoz, and F. Cussó, “High-performance GaN p–n
junction photodetectors for solar ultraviolet applications,” Semicond. Sci. Technol., vol. 13, pp. 1042-1046, June 1998.
[11] G. Parish, S. Keller, P. Kozodoy, J. A. Ibbetson, H. Marchand, P. T. Fini,
S. B. Fleischer, S. P. DenBaars, and U. K. Mishra, “High performance
(Al,Ga)N-based solar-blind ultraviolet p–i–n detectors on laterally
epitaxially overgrown GaN,” Appl. Phys. Lett., vol. 75, pp. 247-249, July 1999.
[12] E. Monroy, M. Hamilton, D. Walker, P. Kung, F. J. Sánchez, and M.
Razeghi, “High quality visible-blind algan p–i–n photodiodes,” Appl.
Phys. Lett., vol. 74, pp. 1171-1173, Feb. 1999.
[13] A. Osinsky, S. Gangopadhyay, R. Gaska, B. Williams, M. A. Khan, D.
Kuksenkov, and H. Temkin, “Low noise p-π-n GaN ultraviolet
photodetectors,” Appl. Phys. Lett., vol. 71, pp. 2334-2336, Oct. 1997.
[14] Q. Chen, J. W. Yang, A. Osinsky, S. Gangopadhyay, B. Lim, M. Z.
Anwar, M. A. Khan, D. Kuksenkov, and H. Temkin, “Schottky barrier
detectors on GaN for visible-blind ultraviolet detection,” Appl. Phys.
Lett., vol. 70, pp. 2277-2279, Apr. 1997.
[15] Z. C. Huang, J. C. Chen, and D. Wickenden, “Characterization of GaN
using thermally stimulated current and photocurrent spectroscopies and
its application to UV detectors,” J. Cryst. Growth, vol. 170, pp. 362-362,
Jan. 1997.
[16] C. H. Chen, S. J. Chang, Y. K. Su, G. C. Chi, J. Y. Chi, C. A. Chang, J.
K. Sheu, and J. F. Chen, “GaN metal-semiconductor-metal ultraviolet
photodetectors with transparent indium-tin-oxide Schottky contacts,”
IEEE Photon. Technol. Lett., vol. 13, pp. 848-850, Aug. 2001.
[17] D. Walker, E. Monroy, P. Kung, J. Wu, M. Hamilton, F. J. Sanchez, J.
Diaz, and M. Razeghi, “High speed, low noise metal-semiconducror-
metal ultraviolet photodetectors based on GaN,” Appl. Phys. Lett., vol.
74, pp. 762-764.
[18] S. M. Sze, Semiconductor Device Physics and Technology, pp. 278
(1985)
[19] M.Sze, D. J. Coleman, JR. and A. Loya, Solid-State Electronics,
“Current Transport in Metal-Semiconductor-Metal (MSM) structures”,
Vol. 14, pp. 1209 (1971)
[20] Schubert F. Soares, “Photoconductive Gain in a Schottky Barrier
Photodiode”, Jap. J. Appl. Phys. Vol. 31, pp. 210 (1992)
[21]施敏,”半導體元件物理與製作技術第二版”,國立交通大學出版社
[22] J. C. Campbell, AT&T Bell Lab. Technical Memorendum (unpublished).
[23] S. M. Sze, “Semiconductor Devices Physics and Technology”, Ch.3
[24] Jasprit Singh, “Semiconductor Optoelectronics Physics and
Technology”,Ch. 6 Semiconductor junction theory, p. 286.
[25] G. Dearnaley, J. H. Freeman, R. S. Nelson, Stephen, “Ion-Implantation”,
Ch. 5 Applications to semiconductors, p. 561.
[26] S. R. Forrest, M. DiDomenico, Jr., R. G. Smith, H. J. Stocker,
“Evidence For Tunneling in Reverse-Biased III-V Photodetector
Diodes”, Appl. Phys. Lett., Vol. 36, No. 7, 1 April, 1980, p.580.
[27] S. R. Forrest, R. F. Leheny, R. E. Nahory, M. A. Pollack,
“In0.53Ga0.47As Photodiode With Dark Current Limited by Generation-
Recombination And tunneling”, Appl. Phys. Lett., Vol. 37, No. 3, 1
August, 1981, p. 217.
[28] O. Katz ,V. Garber, B. Meyler, G. Bahir, and J. Salzman , “Anisotropy in
detectivity of GaN Schottky ultraviolet detectors: Comparing lateral and
vertical geometry”, Appl. Phys. Lett., Vol.80, No. 3, 21 January, 2002, p.
347.
[29] K. Kato, “Ultrawide-Band/High-Frequency Photodetectors,” IEEE
Trans.Microwave Theory Tech., vol. 47, pp. 1265-1281, Jul., 1999.
[30] J.E. Bowers and C. A. Burrus, Jr. “Ultrawide-band long-wavelength p-i-n
photodetector”, J. Lightwave Technol., vol. LT-5, pp.1339-1350, 1987.
[31]許晉瑋，金屬-半導體-金屬 行波式光偵測器，國立臺灣大學/光電工
程學研究所博士論文(2001)
[32] T.K. Ko, S.J. Chang, Y.K.Su, M.L. Lee, C.S. Chang, Y.C. Lin, S.C. She,
J.K.Sheu, W.S.Chen, C.F.Shen ,”AlGaN-GaN Schottky-barrier
photodetectors with LT GaN cap layers”, Journal of Crystal Growth,
Volume 283, Issues 1-2, 15 September 2005, Pages 68-71.
[33] J. K. Sheu and G. C. Chi ,”The doping process and dopant characteristics
of GaN”, J. Phys. A 14, R657 2002.
[34] D. J. H. Lambert, M. M. Wong, U. Chowdhury, C. Collins, T. Li, H. K.
Kwon, B. S. Shelton, T. G. Zhu, J. C. Campbell, and R. D. Dupuis, “Back illuminated AlGaN solar-blind photodetectors” ,Appl. Phys. Lett. 77, 1900 2000.
[35] J.-W. Shi, Y.-H. Chen, K. G. Gan, Y. J. Chiu, John. E. Bowers, M.-C.
Tien, T.-M. Liu, and C.-K. Sun, “Nonlinear Behaviors of Low-
Temperature -Grown GaAs-Based Photodetectors Around 1.3-μm
Telecommunication Wavelength” IEEE Photon. Tech. Lett., vol. 16,
pp.242-244, Jan., 2004.
[36] C.-K. Sun, Y.-Hung Chen, J.-W. Shi, Y.-J. Chiu, K. G. Gan, and J. E.
Bowers, “Electron relaxation and transport dynamics in low-
temperature-grown GaAs under 1eV optical excitation” Appl. Phys. Lett., vol. 83, pp. 911-913, Aug., 2003.
[37] C. K. Wang, T. K. Ko, C. S. Chang, S. J. Chang, Y. K. Su, T. C. Wen, C.
H. Kuo, and Y. Z. Chiou,” The Thickness Effect of p-AlGaN Blocking
Layer in UV-A Bandpass Photodetectors”, IEEE Photon. Technol. Lett.,
Volume 17, Issue 10, Oct. 2005 Page(s):2161 – 2163.
[38] P. Kozodoy, J. P. Ibbetson, H. Marchand, P. T. Fini, S. Keller, J. S. Speck,S. P. DenBaars, and U. K. Mishra,” Electrical characterization of GaN p-n junctions with and without threading dislocations” ,Appl. Phys. Lett. 73, 975 1998.