Correlation of biaxial strains, bound exciton energies, and defect microstructures in GaN films grown on AlN/6H-SiC(0001) substrates
Correlation of biaxial strains, bound exciton energies, and defect microstructures in GaN films grown on AlN/6H-SiC(0001) substrates
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DOI：
10.1007/s11664-997-0155-z
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发表时间：
1997-03-01
影响因子：
2.1
通讯作者：
Song, JJ
中科院分区：
文献类型：
--
作者：
Perry, WG;Zheleva, T;Song, JJ
通过改变c轴晶格参数，测量了22个生长在AlN缓冲层上的GaN薄膜的热膨胀系数和晶格参数失配引起的双轴应变。计算泊松比v = 0.18。束缚激子能量（E（BX））是这些应变的线性函数。E（BX）随薄膜应力的位移为23 meV/GPa。对于生长在邻位和轴向SiC上的GaN Rim，分别确定了类似于10（10）/cm（2）和类似于10（8）/cm（2）的螺纹位错密度。通过高分辨透射电子显微镜（HRTEM）观察到GaN/AlN界面处存在0.9%的残余压应变。
Biaxial strains resulting from mismatches in thermal expansion coefficients and lattice parameters in 22 GaN films grown on AlN buffer layers previously deposited on vicinal and on-axis 6H-SiC(0001) substrates were measured via changes in the c-axis lattice parameter. A Poisson's ratio of v = 0.18 was calculated. The bound exciton energy (E(BX)) was a linear function of these strains. The shift in E(BX) with film stress was 23 meV/GPa. Threading dislocations densities of similar to 10(10)/cm(2) and similar to 10(8)/cm(2) were determined for GaN Rims grown on vicinal and on-axis SiC, respectively. A 0.9% residual compressive strain at the GaN/AlN interface was observed by high resolution transmission electron microscopy (HRTEM).