利用金属有机化学气相沉积(MOCVD)技术,在Si(111)衬底上外延生长不同厚度的GaN.外延层薄的GaN表面存在大量的V缺陷,并且V缺陷的两侧有相互平行的带状高坡;外延层厚的GaN表面没有V缺陷,表面平整且晶体质量高.位错处存在晶格畸变,杂质易于在此处聚集,达到一定浓度就会抑制晶体在此处生长而形成V缺陷.受位错附近应力场与气流的影响,V缺陷两侧出现带状高坡.生长时间延长,GaN表面的V缺陷就会被填满,带状高坡横向生长合并成为平整的表面.用m(KOH)∶m(H2O)＝1∶10的KOH溶液腐蚀后,平整的表面出现六角腐蚀坑,密度与原生坑密度相近,认为是原生坑被填满的位置腐蚀后再次出现.
参考文献
| [1] | 康凌,刘宝林,蔡加法,等.掺硅InGaN和掺硅GaN的光学性质的研究 [J].液晶与显示,2004,19(4):266-269. |
| [2] | 危书义,吴花蕊,夏从新,等.耦合GaN/AlxGa1-xN量子点中的激子特性[J].液晶与显示,2005,20(3):190-194. |
| [3] | Vennéguès P,Beaumont B B,Bousquet V,et al.Reduction mechanisms for defect densities in GaN using one-or two-step epitaxy lateral overgrowth methods [J].J.Appl.Phys.,2000,87(9):4175-4181. |
| [4] | Chen Y,Schneider R,Wang S Y,et al.Dislocation reduction in GaN thin films via lateral overgrowth from trenches [J].Appl.Phys.Lett.,1999,75(14):2062-2063. |
| [5] | Bourrent-Courchesne E D,Kellermann S,Yu K M,et al.Reduction of threading dislocation density in GaN using an intermediate temperature interlayer [J].Appl.Phys.Lett.,2000,77(22):3562-3564. |
| [6] | Wang T,Morishima Y,Naoi N,et al.A new method for a great reduction of dislocation density in a GaN layer grown on a sapphire substrate [J].J.Cryst.Growth,2000,213(2):188-192. |
| [7] | Hu G Q,Kong X,Wan L,et al.Microstructure of GaN films grown on Si(111) substrates by metalorganic chemical vapor deposition [J].J.Cryst.Growth,2003,256(4):416-423. |
| [8] | Kotchetkov D,Zou J,Balandin A A,et al.Effect of dislocations on thermal conductivity of GaN layer [J].Appl.Phys.Lett.,2001,79(26):4136-4138. |
| [9] | Qiu X G,Segawa Y,Xue Q K,et al.Photoluminescence of wurtzite GaN thin film on SiC substrate [J].Appl.Phys.Lett.,2000,77(9):1316-1318. |
| [10] | Lisa Sugiura.Dislocation motion in GaN light-emitting devices and its effect on device lifetime [J].J.Appl.Phys.,1997,81(4):1633-1638. |
| [11] | Cherns D,Henley S J,Ponce F A.Edge and screw dislocations as nonradiative centers in InGaN/GaN quantum well luminescence [J].Appl.Phys.Lett.,2001,78(18):2691-2693. |
| [12] | Lin Pei-Yen,YewChung,Wu Sermon.The growth mechanism of micro-size V defects on the hydride vapor phase epitaxy grown undoped GaN films [J].Mater.Chem.Phys.,2003,80(2):397-400. |
| [13] | 魏茂林,齐鸣,李爱珍.横向过生长(LEO)外延GaN材料及其生长机理 [J].功能材料与器件学报,2001,7(2):199-204. |
| [14] | Wen T C,Lee W L,Sheu J K,et al.Observation of dislocation etch pits in epitaxial lateral overgrown GaN by wet etching [J].Solid-State Electron.,2002,46(4):555-558. |
| [15] | Kamler G,Weyher J L,Grzegory I,et al.Defect-selective etching of GaN in a modified molten bases system [J].J.Cryst.Growth,2002,246(1):21-24. |
| [16] | Wu X H,Elsass C R,Abare A,et al.Structural origin of V-defects and correlation with localized excitonic centers in InGaN/GaN multiple quantum wells [J].Appl.Phys.Lett.,1998,72(6):692-694. |
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