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研究了不同Ni厚度的Ni/Ag/Ti/Au电极在不同退火温度和退火气氛下与p-GaN之间的欧姆接触性能以及电极的光反射率的变化. 采用矩形传输线模型对各电极的比接触电阻率进行测算，利用分光光度计对电极在不同波长下的反射率进行测量. 结果表明，Ni金属层的厚度越小，电极的光反射率越高，而Ni层厚度对比接触电阻率的影响较小；当退火温度高于400 ℃后，电极的光反射率降低，在氧气氛围中退火后光反射率比在氮气中退火后下降更加明显. 但在氧气氛围中退火有利于减小比接触电阻率. 综合考虑接触电阻和光反射率，电极Ni（1 nm）/Ag/Ti/Au在400 ℃氧气中快速退火后得到了较好的结果，其比接触电阻率为5.5×10-3 Ω·cm2，在450 nm 处反射率为85%. 利用此电极制作了垂直结构发光二极管（LED）器件，LED在350 mA注入电流下，工作电压为3.2 V，发光功率为270 mW，电光转换效率达到24%.The ohmic reflectivity of Ni/Ag/Ti/Au in contact with p-GaN is studied. It is found that under different thickness values of Ni, different annealing temperatures and different annealing atmospheres, the performances of Ni/Ag/Ti/Au electrode are greatly changed. The contact resistivity is measured using the transmission line model. The reflectivity of the electrode is investigated by using a spectrophotometer. The results reveal that the thinner the Ni metal layer, the higher its reflectivity is, in addition, the thickness value of Ni metal has a little influence on contact resistivity. There appears an abrupt decrease in reflectivity of electrode after annealing at a temperature higher than 400 ℃. It is noticed that the reflectivity decreases more sharply after annealing in oxygen atmosphere than in nitrogen atmosphere. However, annealing in oxygen atmosphere is more helpful to reduce the contact resistivity. The comprehensive evaluations of the contact resistivity and reflectivity indicate that the better performances of Ni (1 nm)/Ag/Ti/Au electrode after rapid annealing in oxygen atmosphere at 400 ℃ are achieved: its contact resistance reaches 5.5× 10-3 Ω·cm2 and reflectivity rises up to 85% at 450 nm. Light emitting diode (LED) of vertical structure is fabricated with an optimal electrode. The LED under an injection current of 350 mA can achieve the following working parameters: the working voltage is 3.2 V, the optical output power is 270 mW, and the electro-optical conversion efficiency is 24%.
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Keywords:
- p-GaN /
- ohmic contact /
- reflectivity /
- rapidly thermal annealing
[1] Ponce F A, Bour D P 1997 Nature 386 351
[2] Yang L, Ma X H, Feng Q, Hao Y 2008 Chin. Phys. B 17 7
[3] Ding Z B, Yao S D, Wang K, Cheng K 2006 Acta Phys. Sin. 55 2977 (in Chinese)[丁志博, 姚淑德, 王坤, 程凯 2006 物理学报 55 2977]
[4] Xue Z Q, Huang S R, Zhang B P, Chen C 2010 Acta Phys. Sin. 59 1268 (in Chinese)[薛正群, 黄生荣, 张保平, 陈朝 2010 物理学报 59 1268]
[5] Park J, Shin M, Lee C C 2004 Opt. Lett. 29 2656
[6] Kim H, Choi K K, Kim K K, Cho J, Lee S N, Park Y, Kwak J S, Seong T Y 2008 Opt. Lett. 33 1273
[7] Zheng C, Zhang S M, Wang H, Liu J P, Wang H B, Li Z C, Feng M X, Zhao D G, Liu Z S, Jiang D S, Yang H 2012 Chin. Phys. Lett. 29 017301
[8] Maeda T, Koide Y, Murakami M 1999 Appl. Phys. Lett. 75 4145
[9] Li X J, Zhao D G, He X G, Wu L L, Li L, Yang J, Le L C, Chen P, Liu Z S, Jiang D S 2013 Acta Phys. Sin. 62 206801 (in Chinese)[李晓静, 赵德刚, 何晓光, 吴亮亮, 李亮, 杨静, 乐伶聪, 陈平, 刘宗顺, 江德生 2013 物理学报 62 206801]
[10] Chang L B, Shire C C, Jeng M J 2007 Appl. Phys. Lett. 90 163515
[11] Jang H W, Lee J L 2004 Appl. Phys. Lett. 85 5920
[12] Song J O, Kwak J S, Park Y, Seong T Y 2005 Appl. Phys. Lett. 86 062104
[13] Kim K S, Suh M G, Cho S N 2012 Appl. Phys. Lett. 100 061113
[14] Wu D F, Yan B D 1989 Principle, Measurement and Processing of Ohmic Contacts on Metal-Semiconductor Interface (Shanghai: Shanghai Jiaotong University Press) p8 (in Chinese) [吴鼎芬, 颜本达 1989 金属-半导体界面欧姆接触的原理、测试与工艺 (上海: 上海交通大学出版社) 第8页]
[15] Jang H W, Kim S Y, Lee J L 2003 J. Appl. Phys. 94 1748
[16] Lin Y J 2004 Appl. Phys. Lett. 84 2760
[17] Greco G, Prystawko P, Leszczy'nski M, Nigro R L, Raineri V, Roccaforte F 2011 J. Appl. Phys. 110 123703
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[1] Ponce F A, Bour D P 1997 Nature 386 351
[2] Yang L, Ma X H, Feng Q, Hao Y 2008 Chin. Phys. B 17 7
[3] Ding Z B, Yao S D, Wang K, Cheng K 2006 Acta Phys. Sin. 55 2977 (in Chinese)[丁志博, 姚淑德, 王坤, 程凯 2006 物理学报 55 2977]
[4] Xue Z Q, Huang S R, Zhang B P, Chen C 2010 Acta Phys. Sin. 59 1268 (in Chinese)[薛正群, 黄生荣, 张保平, 陈朝 2010 物理学报 59 1268]
[5] Park J, Shin M, Lee C C 2004 Opt. Lett. 29 2656
[6] Kim H, Choi K K, Kim K K, Cho J, Lee S N, Park Y, Kwak J S, Seong T Y 2008 Opt. Lett. 33 1273
[7] Zheng C, Zhang S M, Wang H, Liu J P, Wang H B, Li Z C, Feng M X, Zhao D G, Liu Z S, Jiang D S, Yang H 2012 Chin. Phys. Lett. 29 017301
[8] Maeda T, Koide Y, Murakami M 1999 Appl. Phys. Lett. 75 4145
[9] Li X J, Zhao D G, He X G, Wu L L, Li L, Yang J, Le L C, Chen P, Liu Z S, Jiang D S 2013 Acta Phys. Sin. 62 206801 (in Chinese)[李晓静, 赵德刚, 何晓光, 吴亮亮, 李亮, 杨静, 乐伶聪, 陈平, 刘宗顺, 江德生 2013 物理学报 62 206801]
[10] Chang L B, Shire C C, Jeng M J 2007 Appl. Phys. Lett. 90 163515
[11] Jang H W, Lee J L 2004 Appl. Phys. Lett. 85 5920
[12] Song J O, Kwak J S, Park Y, Seong T Y 2005 Appl. Phys. Lett. 86 062104
[13] Kim K S, Suh M G, Cho S N 2012 Appl. Phys. Lett. 100 061113
[14] Wu D F, Yan B D 1989 Principle, Measurement and Processing of Ohmic Contacts on Metal-Semiconductor Interface (Shanghai: Shanghai Jiaotong University Press) p8 (in Chinese) [吴鼎芬, 颜本达 1989 金属-半导体界面欧姆接触的原理、测试与工艺 (上海: 上海交通大学出版社) 第8页]
[15] Jang H W, Kim S Y, Lee J L 2003 J. Appl. Phys. 94 1748
[16] Lin Y J 2004 Appl. Phys. Lett. 84 2760
[17] Greco G, Prystawko P, Leszczy'nski M, Nigro R L, Raineri V, Roccaforte F 2011 J. Appl. Phys. 110 123703
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