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利用卢瑟福背散射/沟道技术和高分辨率X射线衍射技术对在Si(111)衬底上利用金属有机化合物气相外延技术(MOVPE)生长有多缓冲层的六方GaN外延膜进行结晶品质计算、晶格常数计算和应变分析.实验结果表明:GaN外延膜的结晶品质为χmin=1·54%,已达到完美晶体的结晶品质(χmin=1%—2%);GaN外延膜的水平方向和垂直方向晶格常数分别为:aepi=0·31903nm,cepi=0·51837nm,基本达到GaN单晶的理论晶格常数(a0=0·3189nm,c0=0·5186nm);通过计算GaN外延膜及各缓冲层的水平应变、垂直应变和四方畸变沿深度的变化,可得出弹性应变由衬底及各缓冲层向表面逐渐释放,并由拉应变转为压应变,最后在GaN外延层应变基本达到完全释放(eT=0).
Using Rutherford backscattering / channeling technique and high-resolution X-ray diffraction technique, the hexagonal GaN epitaxial films grown on Si (111) substrate by metal organic compound vapor phase epitaxy (MOVPE) The results show that the crystalline quality of GaN epitaxial film is χ min = 1.54%, and the crystal quality of perfect crystal has been reached (χ min = 1% -2%). The level of GaN epitaxial film The lattice constants in the directions and vertical directions are as follows: aepi = 0.31903 nm, cepi = 0.18537 nm, which basically reach the theoretical lattice constant of GaN single crystal (a0 = 0.3189 nm, c0 = 0.1856 nm) The results show that the elastic strain is gradually released from the substrate and the buffer layers to the surface and transferred from tensile strain to compressive strain. Finally, the GaN epitaxial layer Strain basically reached full release (eT = 0).