Citation: |
Liang Jing, Hongling Xiao, Xiaoliang Wang, Cuimei Wang, Qingwen Deng, Zhidong Li, Jieqin Ding, Zhanguo Wang, Xun Hou. The growth and characterization of GaN films on cone-shaped patterned sapphire by MOCVD[J]. Journal of Semiconductors, 2013, 34(11): 113002. doi: 10.1088/1674-4926/34/11/113002
****
L Jing, H L Xiao, X L Wang, C M Wang, Q W Deng, Z D Li, J Q Ding, Z G Wang, X Hou. The growth and characterization of GaN films on cone-shaped patterned sapphire by MOCVD[J]. J. Semicond., 2013, 34(11): 113002. doi: 10.1088/1674-4926/34/11/113002.
|
The growth and characterization of GaN films on cone-shaped patterned sapphire by MOCVD
DOI: 10.1088/1674-4926/34/11/113002
More Information
-
Abstract
GaN films are grown on cone-shaped patterned sapphire substrates (CPSSs) by metal-organic chemical vapor deposition, and the influence of the temperature during the middle stage of GaN growth on the threading dislocation (TD) density of GaN is investigated. High-resolution X-ray diffraction (XRD) and cathode-luminescence (CL) were used to characterize the GaN films. The XRD results showed that the edge-type dislocation density of GaN grown on CPSS is remarkably reduced compared to that of GaN grown on conventional sapphire substrates (CSSs). Furthermore, when the growth temperature in the middle stage of GaN grown on CPSS decreases, the full width at half maximum of the asymmetry (102) plane of GaN is reduced. This reduction is attributed to the enhancement of vertical growth in the middle stage with a more triangular-like shape and the bending of TDs. The CL intensity spatial mapping results also showed the superior optical properties of GaN grown on CPSS to those of GaN on CSS, and that the density of dark spots of GaN grown on CPSS induced by nonradiative recombination is reduced when the growth temperature in the middle stage decreases. -
References
[1] Wang X L, Wang C M, Hu G X, et al. Improved DC and RF performance of AlGaN/GaN HEMTs grown by MOCVD on sapphire substrates. Solid-State Electron, 2005, 49(8):1387 doi: 10.1016/j.sse.2005.06.022[2] Ponce F, Bour D. Nitride-based semiconductors for blue and green light-emitting devices. Nature, 1997, 386(6623):351 doi: 10.1038/386351a0[3] Zhang Xiaobin, Wang Xiaoliang, Xiao Hongling, et al. InGaN/GaN multiple quantum well solar cells with an enhanced open-circuit voltage. Chin Phys B, 2011, 20(2):028402 doi: 10.1088/1674-1056/20/2/028402[4] Elsner J, Jones R, Sitch P K, et al. Theory of threading edge and screw dislocations in GaN. Phys Rev Lett, 1997, 79(19):3672 doi: 10.1103/PhysRevLett.79.3672[5] Sugahara T, Hao M, Wang T, et al. Role of dislocation in InGaN phase separation. Jpn J Appl Phys, 1998, 37:L1195 doi: 10.1143/JJAP.37.L1195[6] Sakai A, Sunakawa H, Usui A. Defect structure in selectively grown GaN films with low threading dislocation density. Appl Phys Lett, 1997, 71(16):2259 doi: 10.1063/1.120044[7] Kato Y, Kitamura S, Hiramatsu K, et al. Selective growth of wurtzite GaN and AlxGa1-xN on GaN/sapphire substrates by metalorganic vapor phase epitaxy. J Cryst Growth, 1994, 144(3/4):133[8] Kitamura S, Hiramatsu K, Sawaki N. Fabrication of GaN hexagonal pyramids on dot-patterned GaN/sapphire substrates via selective metalorganic vapor phase epitaxy. Jpn J Appl Phys, 1995, 34:L1184 doi: 10.1143/JJAP.34.L1184[9] Feng Z H, Qi Y D, Lu Z D, et al. GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy. J Cryst Growth, 2004, 272(1-4):327 doi: 10.1016/j.jcrysgro.2004.08.070[10] Tadatomo K, Okagawa H, Ohuchi Y, et al. High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy. Jpn J Appl Phys, 2001, 40:L583 doi: 10.1143/JJAP.40.L583[11] Gao H, Yan F, Zhang Y, et al. Enhancement of the light output power of InGaN/GaN light-emitting diodes grown on pyramidal patterned sapphire substrates in the micro-and nanoscale. J Appl Phys, 2008, 103(1):014314 doi: 10.1063/1.2830981[12] Rorma P T, Ali M, Svensk O, et al. An investigation of structural properties of GaN films grown on patterned sapphire substrates by MOVPE. Physica B:Condensed Matter, 2009, 404(23/24):4911 doi: 10.1134%2FS1063785015030189.pdf[13] Kissinger S, Jeong S M, Yun S H, et al. Enhancement in emission angle of the blue LED chip fabricated on lens patterned sapphire. Solid-State Electron, 2010, 54(5):509 doi: 10.1016/j.sse.2009.11.005[14] Lee K S, Kwack H S, Hwang J S, et al. Spatial correlation between optical properties and defect formation in GaN thin films laterally overgrown on cone-shaped patterned sapphire substrates. J Appl Phys, 2010, 107(10):103506 doi: 10.1063/1.3388014[15] Lee J H, Lee D Y, Oh B W, et al. Comparison of InGaN-based LEDs grown on conventional sapphire and cone-shape-patterned sapphire substrate. IEEE Trans Electron Devices, 2010, 57(1):157 doi: 10.1109/TED.2009.2034495[16] Wang H W, Chen H C, Chang Y A, et al. Conversion efficiency enhancement of GaN/In0.11Ga0.89N solar cells with nano patterned sapphire and biomimetic surface antireflection process. IEEE Photonics Technol Lett, 2011, 23(18):1304 doi: 10.1109/LPT.2011.2160051[17] Srikant V, Speck J S, Clarke D R. Mosaic structure in epitaxial thin films having large lattice mismatch. J Appl Phys, 1997, 82(9):4286 doi: 10.1063/1.366235[18] Hiramatsu K, Nishiyama K, Onishi M, et al. Fabrication and characterization of low defect density GaN using facet-controlled epitaxial lateral overgrowth (FACELO). J Cryst Growth, 2000, 221(1-4):316 doi: 10.1016/S0022-0248(00)00707-7[19] Kapolnek D, Underwood R D, Keller B P, et al. Selective area epitaxy of GaN for electron field emission devices. J Cryst Growth, 1997, 170(1-4):340 doi: 10.1016/S0022-0248(96)00620-3[20] Kazumasa H. Epitaxial lateral overgrowth techniques used in group Ⅲ nitride epitaxy. J Phys:Condensed Matter, 2001, 13(32):6961 doi: 10.1088/0953-8984/13/32/306 -
Proportional views