臺灣博碩士論文加值系統

本文探討以MOCVD沉積氮化鎵PIN二極體在平面化藍寶石基板Conventional sapphire substrate (CSS) 與圖樣化藍寶石基板Patterned sapphire substrate (PSS) 之上，因不同基板而造成磊晶品質的差異，定量化分析磊晶過程產生的差排缺陷如何影響元件的電特性。在我們的研究過程中發現氮化鎵同樣在在PSS上的磊晶品質會有很大的差異，這部分需配合PSS基板的圖樣結構以及磊晶製程條件，才能使磊晶品質有顯著改善。
文中製作準垂直式PIN二極體，設計不同直徑大小的元件以討論垂直結構的漏電流效應。此外，利用PECVD沉積SiO2 作為側壁鈍化層來降低邊緣電場效應，比較加上鈍化層之前與之後，主導元件崩潰的機制、位置、崩潰電壓的不同來分析鈍化層在元件中的影響。並搭配電流-電壓、電容-電壓特性、變溫DTLS量測，探討內部磊晶缺陷如何影響元件整體的電特性。

Due to the dislocation that resulted from the lattice mismatch between GaN and sapphire substrate, patterned sapphire substrate (PSS) was widely used in MOCVD epitaxy to improve the crystalline quality instead of conventional sapphire substrate (CSS). We compared PIN devices fabricated on FSS with those on PSS to investigate how dislocation affects the devices characteristics, such as forward turn-on voltage, reverse leakage current and breakdown voltage. Following electrical measurement including current-voltage, capacitance-voltage, and deep-level transient spectroscopy (DLTS) were applied in this study.
　Besides, edge effect that resulted from side-wall damage during ICP process is an issue in vertical PIN diodes. To overcome this, SiO2 deposition layer was utilized as side-wall passivation to reduce edge effect. Therefore, we also investigate the breakdown characteristics of diodes to realize the influence of passivation layer.

[1] Ghandhi SK. "Semiconductor power devices". Wiley, 1977 republished 1998.
[2] Q. Wahab, T. Kimoto, A. Ellison, C. Hallin, M. Tuominen, R. Yakimova, A. Henry, J. P. Bergman, and E. Janzen, "A 3 kV Schottky barrier diode in 4H-SiC," Applied Physics Letters, vol. 72, pp. 445-447, Jan 1998.
[3] O. Kordina, J. P. Bergman, A. Henry, E. Janzen, S. Savage, J. Andre, L. P. Ramberg, U. Lindefelt, W. Hermansson, and K. Bergman, "A 4.5 KV 6H SILICON-CARBIDE RECTIFIER," Applied Physics Letters, vol. 67, pp. 1561-1563, Sep 1995.
[4] C. E. Weitzel, J. W. Palmour, C. H. Carter, K. Moore, K. J. Nordquist, S. Allen, C. Thero, and M. Bhatnagar, "Silicon carbide high-power devices," Ieee Transactions on Electron Devices, vol. 43, pp. 1732-1741, Oct 1996.
[5] M. Trivedi and K. Shenai, "Performance evaluation of high-power wide band-gap semiconductor rectifiers," Journal of Applied Physics, vol. 85, pp. 6889-6897, May 1999.
[6] T. G. Zhu, D. J. H. Lambert, B. S. Shelton, M. M. Wong, U. Chowdhury, H. K. Kwon, and R. D. Dupuis, "High-voltage GaN pin vertical rectifiers with 2 um thick i-layer," Electronics Letters, vol. 36, pp. 1971-1972, Nov 2000.
[7] J. T. Torvik, J. I. Pankove, and B. J. Van Zeghbroeck, "Comparison of GaN and 6H-SiC p-i-n photodetectors with excellent ultraviolet sensitivity and selectivity," Ieee Transactions on Electron Devices, vol. 46, pp. 1326-1331, Jul 1999.
[8] J. G. Yang and K. Yang, "GaN-based pin diodes for microwave switching IC applications," Electronics Letters, vol. 48, pp. 650-652, May 2012.
[9] Y. Irokawa, B. Luo, B. S. Kang, J. Kim, J. R. LaRoche, F. Ren, K. H. Baik, S. J. Pearton, C. C. Pan, G. T. Chen, J. I. Chyi, S. S. Park, and Y. J. Park, "2.6 A, 0.69 MW cm(-2) single-chip bulk GaN p-i-n rectifier," Solid-State Electronics, vol. 48, pp. 359-361, Feb 2004.
[10] B. S. Shelton, T. G. Zhu, D. J. H. Lambert, and R. D. Dupuis, "Simulation of the electrical characteristics of high-voltage mesa and planar GaN Schottky and p-i-n rectifiers," Ieee Transactions on Electron Devices, vol. 48, pp. 1498-1502, Aug 2001.
[11] D. Alok, B. J. Baliga, and P. K. McLarty, "A SIMPLE EDGE TERMINATION FOR SILICON-CARBIDE DEVICES WITH NEARLY IDEAL BREAKDOWN VOLTAGE," Ieee Electron Device Letters, vol. 15, pp. 394-395, Oct 1994.
[12] S. Ortolland, "Study of different edge terminations used for 6H-SiC power diodes," Journal De Physique Iii, vol. 7, pp. 809-818, Apr 1997.
[13] A. P. P. Zhang, G. T. Dang, F. Ren, H. Cho, K. P. Lee, S. J. Pearton, J. I. Chyi, T. E. Nee, C. M. Lee, and C. C. Chuo, "Comparison of GaN p-i-n and Schottky rectifier performance," Ieee Transactions on Electron Devices, vol. 48, pp. 407-411, Mar 2001.
[14] http://www.mled-ltd.com/applications/
[15] Y. C. Chang, W. H. Chang, H. C. Chiu, L. T. Tung, C. H. Lee, K. H. Shiu, M. Hong, J. Kwo, J. M. Hong, and C. C. Tsai, "Inversion-channel GaN metal-oxide-semiconductor field-effect transistor with atomic-layer-deposited Al(2)O(3) as gate dielectric," Applied Physics Letters, vol. 93, Aug 2008.
[16] M. L. Huang, Y. C. Chang, C. H. Chang, Y. J. Lee, P. Chang, J. Kwo, T. B. Wu, and M. Hong, "Surface passivation of III-V compound semiconductors using atomic-layer-deposition-grown Al2O3," Applied Physics Letters, vol. 87, Dec 2005.
[17] P. D. Ye, B. Yang, K. K. Ng, J. Bude, G. D. Wilk, S. Halder, and J. C. M. Hwang, "GaN metal-oxide-semiconductor high-electron-mobility-transistor with atomic layer deposited Al2O3 as gate dielectric," Applied Physics Letters, vol. 86, Feb 2005.
[18] A. W. Ott, K. C. McCarley, J. W. Klaus, J. D. Way, and S. M. George, "Atomic layer controlled deposition of Al2O3 films using binary reaction sequence chemistry," Applied Surface Science, vol. 107, pp. 128-136, Nov 1996.
[19] A. C. Dillon, A. W. Ott, J. D. Way, and S. M. George, "SURFACE-CHEMISTRY OF AL2O3 DEPOSITION USING AL(CH3)(3) AND H2O IN A BINARY REACTION SEQUENCE," Surface Science, vol. 322, pp. 230-242, Jan 1995.
[20] M. D. Groner, F. H. Fabreguette, J. W. Elam, and S. M. George, "Low-temperature Al2O3 atomic layer deposition," Chemistry of Materials, vol. 16, pp. 639-645, Feb 2004.
[21] . J. Kim, T. Jeong, and T. G. Kim, "Improved Thermal Stability and Reduced Contact Resistance of Ohmic Contacts on N-Face n-Type GaN With Laser-Assisted Doping," Ieee Electron Device Letters, vol. 34, pp. 372-374, Mar 2013.
[22] G. F. Ye, K. Shi, R. Burke, J. M. Redwing, and S. E. Mohney, "Ti/Al Ohmic Contacts to n-Type GaN Nanowires," Journal of Nanomaterials, 2011.
[23] L. Dobos, B. Pecz, L. Toth, Z. J. Horvath, Z. E. Horvath, E. Horvath, A. Toth, B. Beaumont, and Z. Bougrioua, "Al and Ti/Al contacts on n-GaN," Vacuum, vol. 84, pp. 228-230, Aug 2009.
[24] S. Y. Jung, T. Y. Seong, H. Kim, K. S. Park, J. G. Park, and G. Namgoong, "Electrical Properties of Ti/Al Ohmic Contacts to Sulfur-Passivated N-Face n-Type GaN for Vertical-Structure Light-Emitting Diodes," Electrochemical and Solid State Letters, vol. 12, pp. H275-H277, 2009.
[25] S. Gwo and Y. Lu, "LED display for displaying color image has sub-pixels having LEDs each with transparent nickel/gold (Ni/Au) electrode arranged on p-type gallium nitride (GaN) nanorod," US2012223289-A1.
[26] J. Smalc-Koziorowska, S. Grzanka, E. Litwin-Staszewska, R. Piotrzkowski, G. Nowak, M. Leszczynski, P. Perlin, E. Talik, J. Kozubowski, and S. Krukowski, "Ni-Au contacts to p-type GaN - Structure and properties," Solid-State Electronics, vol. 54, pp. 701-709, Jul 2010.
[27] J. Y. Moon, J. H. Kim, H. S. Lee, C. H. Ahn, H. K. Cho, J. Y. Lee, and H. S. Kim, "Effect of Thermal Annealing on Ni/Au Contact to p-GaN," Journal of the Korean Physical Society, vol. 53, pp. 3681-3684, Dec 2008.
[28] J. S. Jang, K. H. Park, H. K. Jang, H. G. Kim, and S. J. Park, "Ohmic contacts to p-type GaN using a Ni/Pt/Au metallization scheme," Journal of Vacuum Science &; Technology B, vol. 16, pp. 3105-3107, Nov-Dec 1998.
[29] J. S. Jang, H. G. Kim, K. H. Park, C. S. Um, I. K. Han, S. H. Kim, H. K. Jang, and S. J. Park, "Formation of Ni/Pt/Au ohmic contacts to p-GaN," in Nitride Semiconductors. vol. 482, F. A. Ponce, S. P. DenBaars, B. K. Meyer, S. Nakamura, and S. Strite, Eds., ed Warrendale: Materials Research Society, 1998, pp. 1053-1058.
[30] J. S. Jang, S. J. Park, and T. Y. Seong, "Interfacial reaction of Ni/Pt/Au contact schemes to p-type GaN," Journal of the Electrochemical Society, vol. 146, pp. 3425-3428, Sep 1999.
[31] Dieter K. Schroder, "Semiconductor Material and Device Characterization"
[32] Y. Tokuda, Y. Matsuoka, H. Ueda, O. Ishiguro, N. Soejima, and T. Kachi, "DLTS study of n-type GaN grown by MOCVD on GaN substrates," Superlattices and Microstructures, vol. 40, pp. 268-273, Oct-Dec 2006.
[33] D.V. Lang, "Deep‐level transient spectroscopy: A new method to characterize traps in semiconductors," Journal of Applied Physics.
[34] Mike DeVre, Russ Westerman, Graham Muir, Laurent Bellon, "Recent Advances in GaN Dry Etching Process Capabilities"
[35] D. Zhuang, J.H. Edgar, “Wet etching of GaN, AlN, and SiC: a review,” Mater. Sci. Eng. R-Rep., vol. 48, pp. 1-46, Jan, 2005
[36] Kozodoy, P.; Ibbetson, J. P.; Marchand, H.; Fini, P. T.; Keller, S.; Speck, J. S.; DenBaars, S. P.; Mishra, U. K., “Electrical characterization of GaN p-n junctions with and without threading dislocations,” Appl. Phys. Lett., vol . 73, no 7, Aug, 1998
[37] E. J. Miller, E. T. Yu, P. Waltereit, and J. S. Speck, “Analysis of reverse-bias leakage current mechanisms in GaN grown by molecular-beam epitaxy,” Appl. Phys. Lett., vol . 84, no 4, pp. 535-537, Jan, 2004
[38] Anping P. Zhang, Gerard T. Dang, Fan Ren, Member, IEEE, Hyun Cho, Kyu-Pil Lee, Stephen J. Pearton, Fellow, IEEE, Jenn-Inn Chyi, T.-E. Nee, C.-M. Lee, and C.-C. Chuo, “Comparison of GaN P-I-N and Schottky Rectifier Performance,” IEEE T ELECTRON DEV. vol . 48, no 3, pp. 407-411, Mar, 2001
[39] P. Bogusl/awski, E. L. Briggs, and J. Bernholc, “Native defects in gallium nitride,” Phys. Rev. B, vol. 51, no. 23, pp. 17255-17258
[40] Z.-Q. Fanga, D. C. Look, X.-L. Wang, Jung Han, F. A. Khan and I. Adesida, “Plasma-etching-enhanced deep centers in n-GaN grown by metalorganic chemical-vapor deposition,” Appl. Phys. Lett., vol . 82, no. 10, pp. 1562-1564, Mar, 2003
[41] Z-Q. FANG,1 D.C. LOOK,1 C. LU,2 and H. MORKOÇ, “Electron and Hole Traps in GaN p-i-n Photodetectors Grown by Reactive Molecular Beam Epitaxy,” J. Electron. Mater. vol . 29, no. 9, pp. L19-L23, Jun, 2000
[42] [1] Y. Tokudaa, Y. Matsuokaa, H. Uedab, O. Ishigurob, N. Soejima and T. Kachi, “DLTS study of n-type GaN grown by MOCVD on GaN substrates,” Elsevier Ltd. superlattices and microstructures, vol.40 ,pp. 268-273, Sep, 2006
[43] H. M. Chen, Y. F. Chen, M. C. Lee and M. S. Feng, “Yellow luminescence in n-type GaN epitaxial films,” Phys. Rev. B, vol. 56, no. 11, pp. 6942-6946, Sep, 1997
[44] E. Calleja, F. J. Sa´nchez, D. Basak, M. A. Sa´nchez-Garcı´a, E. Mun˜oz, I. Izpura, F. Calle, J. M. G. Tijero, and J. L. Sa´nchez-Rojas, “Yellow luminescence and related deep states in undoped GaN,” Phys. Rev. B, vol. 55, no. 7, pp. 4689-4694, Feb, 1997

[1] Ghandhi SK. "Semiconductor power devices". Wiley, 1977 republished 1998.
[2] Q. Wahab, T. Kimoto, A. Ellison, C. Hallin, M. Tuominen, R. Yakimova, A. Henry, J. P. Bergman, and E. Janzen, "A 3 kV Schottky barrier diode in 4H-SiC," Applied Physics Letters, vol. 72, pp. 445-447, Jan 1998.
[3] O. Kordina, J. P. Bergman, A. Henry, E. Janzen, S. Savage, J. Andre, L. P. Ramberg, U. Lindefelt, W. Hermansson, and K. Bergman, "A 4.5 KV 6H SILICON-CARBIDE RECTIFIER," Applied Physics Letters, vol. 67, pp. 1561-1563, Sep 1995.
[4] C. E. Weitzel, J. W. Palmour, C. H. Carter, K. Moore, K. J. Nordquist, S. Allen, C. Thero, and M. Bhatnagar, "Silicon carbide high-power devices," Ieee Transactions on Electron Devices, vol. 43, pp. 1732-1741, Oct 1996.
[5] M. Trivedi and K. Shenai, "Performance evaluation of high-power wide band-gap semiconductor rectifiers," Journal of Applied Physics, vol. 85, pp. 6889-6897, May 1999.
[6] T. G. Zhu, D. J. H. Lambert, B. S. Shelton, M. M. Wong, U. Chowdhury, H. K. Kwon, and R. D. Dupuis, "High-voltage GaN pin vertical rectifiers with 2 um thick i-layer," Electronics Letters, vol. 36, pp. 1971-1972, Nov 2000.
[7] J. T. Torvik, J. I. Pankove, and B. J. Van Zeghbroeck, "Comparison of GaN and 6H-SiC p-i-n photodetectors with excellent ultraviolet sensitivity and selectivity," Ieee Transactions on Electron Devices, vol. 46, pp. 1326-1331, Jul 1999.
[8] J. G. Yang and K. Yang, "GaN-based pin diodes for microwave switching IC applications," Electronics Letters, vol. 48, pp. 650-652, May 2012.
[9] Y. Irokawa, B. Luo, B. S. Kang, J. Kim, J. R. LaRoche, F. Ren, K. H. Baik, S. J. Pearton, C. C. Pan, G. T. Chen, J. I. Chyi, S. S. Park, and Y. J. Park, "2.6 A, 0.69 MW cm(-2) single-chip bulk GaN p-i-n rectifier," Solid-State Electronics, vol. 48, pp. 359-361, Feb 2004.
[10] B. S. Shelton, T. G. Zhu, D. J. H. Lambert, and R. D. Dupuis, "Simulation of the electrical characteristics of high-voltage mesa and planar GaN Schottky and p-i-n rectifiers," Ieee Transactions on Electron Devices, vol. 48, pp. 1498-1502, Aug 2001.
[11] D. Alok, B. J. Baliga, and P. K. McLarty, "A SIMPLE EDGE TERMINATION FOR SILICON-CARBIDE DEVICES WITH NEARLY IDEAL BREAKDOWN VOLTAGE," Ieee Electron Device Letters, vol. 15, pp. 394-395, Oct 1994.
[12] S. Ortolland, "Study of different edge terminations used for 6H-SiC power diodes," Journal De Physique Iii, vol. 7, pp. 809-818, Apr 1997.
[13] A. P. P. Zhang, G. T. Dang, F. Ren, H. Cho, K. P. Lee, S. J. Pearton, J. I. Chyi, T. E. Nee, C. M. Lee, and C. C. Chuo, "Comparison of GaN p-i-n and Schottky rectifier performance," Ieee Transactions on Electron Devices, vol. 48, pp. 407-411, Mar 2001.
[14] http://www.mled-ltd.com/applications/
[15] Y. C. Chang, W. H. Chang, H. C. Chiu, L. T. Tung, C. H. Lee, K. H. Shiu, M. Hong, J. Kwo, J. M. Hong, and C. C. Tsai, "Inversion-channel GaN metal-oxide-semiconductor field-effect transistor with atomic-layer-deposited Al(2)O(3) as gate dielectric," Applied Physics Letters, vol. 93, Aug 2008.
[16] M. L. Huang, Y. C. Chang, C. H. Chang, Y. J. Lee, P. Chang, J. Kwo, T. B. Wu, and M. Hong, "Surface passivation of III-V compound semiconductors using atomic-layer-deposition-grown Al2O3," Applied Physics Letters, vol. 87, Dec 2005.
[17] P. D. Ye, B. Yang, K. K. Ng, J. Bude, G. D. Wilk, S. Halder, and J. C. M. Hwang, "GaN metal-oxide-semiconductor high-electron-mobility-transistor with atomic layer deposited Al2O3 as gate dielectric," Applied Physics Letters, vol. 86, Feb 2005.
[18] A. W. Ott, K. C. McCarley, J. W. Klaus, J. D. Way, and S. M. George, "Atomic layer controlled deposition of Al2O3 films using binary reaction sequence chemistry," Applied Surface Science, vol. 107, pp. 128-136, Nov 1996.
[19] A. C. Dillon, A. W. Ott, J. D. Way, and S. M. George, "SURFACE-CHEMISTRY OF AL2O3 DEPOSITION USING AL(CH3)(3) AND H2O IN A BINARY REACTION SEQUENCE," Surface Science, vol. 322, pp. 230-242, Jan 1995.
[20] M. D. Groner, F. H. Fabreguette, J. W. Elam, and S. M. George, "Low-temperature Al2O3 atomic layer deposition," Chemistry of Materials, vol. 16, pp. 639-645, Feb 2004.
[21] . J. Kim, T. Jeong, and T. G. Kim, "Improved Thermal Stability and Reduced Contact Resistance of Ohmic Contacts on N-Face n-Type GaN With Laser-Assisted Doping," Ieee Electron Device Letters, vol. 34, pp. 372-374, Mar 2013.
[22] G. F. Ye, K. Shi, R. Burke, J. M. Redwing, and S. E. Mohney, "Ti/Al Ohmic Contacts to n-Type GaN Nanowires," Journal of Nanomaterials, 2011.
[23] L. Dobos, B. Pecz, L. Toth, Z. J. Horvath, Z. E. Horvath, E. Horvath, A. Toth, B. Beaumont, and Z. Bougrioua, "Al and Ti/Al contacts on n-GaN," Vacuum, vol. 84, pp. 228-230, Aug 2009.
[24] S. Y. Jung, T. Y. Seong, H. Kim, K. S. Park, J. G. Park, and G. Namgoong, "Electrical Properties of Ti/Al Ohmic Contacts to Sulfur-Passivated N-Face n-Type GaN for Vertical-Structure Light-Emitting Diodes," Electrochemical and Solid State Letters, vol. 12, pp. H275-H277, 2009.
[25] S. Gwo and Y. Lu, "LED display for displaying color image has sub-pixels having LEDs each with transparent nickel/gold (Ni/Au) electrode arranged on p-type gallium nitride (GaN) nanorod," US2012223289-A1.
[26] J. Smalc-Koziorowska, S. Grzanka, E. Litwin-Staszewska, R. Piotrzkowski, G. Nowak, M. Leszczynski, P. Perlin, E. Talik, J. Kozubowski, and S. Krukowski, "Ni-Au contacts to p-type GaN - Structure and properties," Solid-State Electronics, vol. 54, pp. 701-709, Jul 2010.
[27] J. Y. Moon, J. H. Kim, H. S. Lee, C. H. Ahn, H. K. Cho, J. Y. Lee, and H. S. Kim, "Effect of Thermal Annealing on Ni/Au Contact to p-GaN," Journal of the Korean Physical Society, vol. 53, pp. 3681-3684, Dec 2008.
[28] J. S. Jang, K. H. Park, H. K. Jang, H. G. Kim, and S. J. Park, "Ohmic contacts to p-type GaN using a Ni/Pt/Au metallization scheme," Journal of Vacuum Science &; Technology B, vol. 16, pp. 3105-3107, Nov-Dec 1998.
[29] J. S. Jang, H. G. Kim, K. H. Park, C. S. Um, I. K. Han, S. H. Kim, H. K. Jang, and S. J. Park, "Formation of Ni/Pt/Au ohmic contacts to p-GaN," in Nitride Semiconductors. vol. 482, F. A. Ponce, S. P. DenBaars, B. K. Meyer, S. Nakamura, and S. Strite, Eds., ed Warrendale: Materials Research Society, 1998, pp. 1053-1058.
[30] J. S. Jang, S. J. Park, and T. Y. Seong, "Interfacial reaction of Ni/Pt/Au contact schemes to p-type GaN," Journal of the Electrochemical Society, vol. 146, pp. 3425-3428, Sep 1999.
[31] Dieter K. Schroder, "Semiconductor Material and Device Characterization"
[32] Y. Tokuda, Y. Matsuoka, H. Ueda, O. Ishiguro, N. Soejima, and T. Kachi, "DLTS study of n-type GaN grown by MOCVD on GaN substrates," Superlattices and Microstructures, vol. 40, pp. 268-273, Oct-Dec 2006.
[33] D.V. Lang, "Deep‐level transient spectroscopy: A new method to characterize traps in semiconductors," Journal of Applied Physics.
[34] Mike DeVre, Russ Westerman, Graham Muir, Laurent Bellon, "Recent Advances in GaN Dry Etching Process Capabilities"
[35] D. Zhuang, J.H. Edgar, “Wet etching of GaN, AlN, and SiC: a review,” Mater. Sci. Eng. R-Rep., vol. 48, pp. 1-46, Jan, 2005
[36] Kozodoy, P.; Ibbetson, J. P.; Marchand, H.; Fini, P. T.; Keller, S.; Speck, J. S.; DenBaars, S. P.; Mishra, U. K., “Electrical characterization of GaN p-n junctions with and without threading dislocations,” Appl. Phys. Lett., vol . 73, no 7, Aug, 1998
[37] E. J. Miller, E. T. Yu, P. Waltereit, and J. S. Speck, “Analysis of reverse-bias leakage current mechanisms in GaN grown by molecular-beam epitaxy,” Appl. Phys. Lett., vol . 84, no 4, pp. 535-537, Jan, 2004
[38] Anping P. Zhang, Gerard T. Dang, Fan Ren, Member, IEEE, Hyun Cho, Kyu-Pil Lee, Stephen J. Pearton, Fellow, IEEE, Jenn-Inn Chyi, T.-E. Nee, C.-M. Lee, and C.-C. Chuo, “Comparison of GaN P-I-N and Schottky Rectifier Performance,” IEEE T ELECTRON DEV. vol . 48, no 3, pp. 407-411, Mar, 2001
[39] P. Bogusl/awski, E. L. Briggs, and J. Bernholc, “Native defects in gallium nitride,” Phys. Rev. B, vol. 51, no. 23, pp. 17255-17258
[40] Z.-Q. Fanga, D. C. Look, X.-L. Wang, Jung Han, F. A. Khan and I. Adesida, “Plasma-etching-enhanced deep centers in n-GaN grown by metalorganic chemical-vapor deposition,” Appl. Phys. Lett., vol . 82, no. 10, pp. 1562-1564, Mar, 2003
[41] Z-Q. FANG,1 D.C. LOOK,1 C. LU,2 and H. MORKOÇ, “Electron and Hole Traps in GaN p-i-n Photodetectors Grown by Reactive Molecular Beam Epitaxy,” J. Electron. Mater. vol . 29, no. 9, pp. L19-L23, Jun, 2000
[42] [1] Y. Tokudaa, Y. Matsuokaa, H. Uedab, O. Ishigurob, N. Soejima and T. Kachi, “DLTS study of n-type GaN grown by MOCVD on GaN substrates,” Elsevier Ltd. superlattices and microstructures, vol.40 ,pp. 268-273, Sep, 2006
[43] H. M. Chen, Y. F. Chen, M. C. Lee and M. S. Feng, “Yellow luminescence in n-type GaN epitaxial films,” Phys. Rev. B, vol. 56, no. 11, pp. 6942-6946, Sep, 1997
[44] E. Calleja, F. J. Sa´nchez, D. Basak, M. A. Sa´nchez-Garcı´a, E. Mun˜oz, I. Izpura, F. Calle, J. M. G. Tijero, and J. L. Sa´nchez-Rojas, “Yellow luminescence and related deep states in undoped GaN,” Phys. Rev. B, vol. 55, no. 7, pp. 4689-4694, Feb, 1997