Epitaxial GaN films were grown on c-sapphire by rf magnetron reactive sputtering of GaAs at different partial pressures of nitrogen in Ar–N₂ sputtering atmosphere. High-resolution x-ray diffraction and φ-scans reveal the mosaic growth of c-axis oriented, wurtzite GaN films. The c and a parameters were independently determined to obtain the corresponding in-plane and out-of-plane strain components. Raman measurements confirmed the in-plane strain behavior. The surface morphology and elemental composition of films were studied by atomic force microscopy and secondary ion mass spectroscopy, respectively. High-resolution ω-2θ, ω, and in-plane φ-rocking curve scans were used to obtain micro-strain, screw and edge dislocation densities, respectively. The films grown at 30%–100% N₂ reveal dominance of edge (∼10¹² cm⁻²) over screw (∼10¹⁰ cm⁻²) dislocations, with both approaching similar densities at lower N₂ percentages. The strain data has been analyzed to separate the hydrostatic and biaxial contributions and their dependences on N₂ percentage. The film grown at 100% N₂ displays large hydrostatic strain and micro-strain due to the presence of excess/interstitial nitrogen. The hydrostatic strain and micro-strain decrease substantially with initial decrease of N₂ percentage, but increase slightly in the films grown below 30% N₂, primarily due to the incorporation of Ar. The films grown below 75% N₂ display growth-related intrinsic tensile stress, originating from crystallite coalescence. The stress reversal from tensile to compressive, seen in the films grown at higher N₂ percentages is primarily attributed to the incorporation of excess/interstitial nitrogen into grain boundaries and the tensile side of edge dislocations. The decrease of intrinsic tensile stress in the films grown below 30% N₂ is attributed to the incorporation of Ar and their voided structure.

在r–N ₂溅射气氛中，在不同的氮气分压下，通过射频磁控反应性GaAs反应溅射GaAs，在c蓝宝石上生长了外延GaN膜。高分辨率X射线衍射和φ扫描揭示了c轴取向纤锌矿GaN膜的镶嵌生长。所述Ç和一个被独立地确定的参数，以获得相应的在面内和面外应变分量。拉曼测量证实了面内应变行为。分别通过原子力显微镜和二次离子质谱研究了膜的表面形态和元素组成。高分辨率ω- 2 θ，ω，和平面φ摇摆曲线扫描分别用于获得微应变，螺钉和边缘位错密度。在30％–100％N _2下生长的膜显示出边缘（〜10 ¹² cm ^-2）比螺丝（〜10 ¹⁰ cm ^-2）位错占优势，并且在较低的N ₂百分比下，两者的密度相似。分析了应变数据以分离静水和双轴作用及其对N ₂百分比的依赖性。薄膜在100％N _2下生长由于存在过量/间隙氮，因此显示出较大的静液压应变和微应变。随着N ₂百分比的初始降低，流体静应变和微应变显着降低，但在低于30％N ₂的薄膜中，其静应变和微应变则有所增加，这主要归因于Ar的引入。在75％N ₂以下生长的薄膜显示出与生长相关的固有拉伸应力，该应力源自微晶聚结。在以较高的N ₂百分比生长的薄膜中看到的应力从拉伸到压缩的反转主要归因于过量/间隙氮掺入晶界和边缘位错的拉伸侧。氮含量低于30％时薄膜固有拉伸应力的降低₂归因于Ar及其空隙结构的结合。