论文标题
在反应溅射的外延SI掺杂膜中的残留应力研究
Study of residual stress in reactively sputtered epitaxial Si-doped GaN films
论文作者
论文摘要
Si掺杂的GAN膜是在$ \ textit {c} $ - rf Magnetron的蓝宝石上，由RF Magnetron反应性共同投放GAA和SI在AR-N2增长气氛中的各种部分压力下，在各种局部压力下，Phi-Scans确定了它们的外延。能量分散X射线光谱显示所有膜中的$ \厚度为2美元，但随着n $ _2 $百分比从100％降低到10％，N/GA比大幅下降。高分辨率的X射线衍射显示了边缘位错的主要存在（$ \厚$ 10 $^{12} $ cm $ $^{ - 2} $）在30％-100％n $ _2 $上生长的电影中，该$ _2 $降低至$ 5 x 10 $^$ 5 x $ cm $^$^$^$^$^$^$^$^$^$^2}发现螺钉位错的增加和达到的值与边缘位错相当。独立地获得了晶格参数（$ \ textit {a} $和$ \ textit {c} $），以确定薄膜中应变的平面内和平面成分，这些分析被分析以推断出液压和双轴菌株的贡献。该膜以100％n $ _2 $生长，由于过量/间隙氮而显示大型微型固定和静液压菌株，这两种脂肪随着N $ _2 $ table的初始降低而减少，但由于AR掺入而导致的n $ _2 $百分比最初减少。这些薄膜生长在75％n $ _2 $以上的薄膜表现出压缩双轴应力，这归因于氮的可能掺入晶界和边缘位错的拉伸侧。在合并期间产生的平面内拉力应力的患病率解释了低于75％n $ _2 $的膜中双轴应力向拉伸特征的逆转。在30％n $ _2 $的薄膜中，拉伸应力降低，这归因于AR掺入和变白的形态。膜中Si的存在对应变行为没有重大影响，并且似乎被主要的生长相关的内在效应所掩盖。
Si-doped GaN films were grown on $\textit{c}$-sapphire by rf magnetron reactive co-sputtering of GaAs and Si at various partial pressures of N$_2$ in Ar-N2 growth atmosphere and their epitaxial character was ascertained by phi-scans. Energy dispersive x-ray spectroscopy revealed $\thicksim$2 at.% Si in all the films, but the N/Ga ratio decreased substantially as N$_2$ percentage was reduced from 100% to 10%. High resolution x-ray diffraction revealed the dominant presence of edge dislocations ($\thicksim$10$^{12}$ cm$^{-2}$) in the films grown at 30% - 100% N$_2$, which decreased to $\thicksim$5 x 10$^{11}$ cm$^{-2}$ at lower N$_2$ percentages, at which, the density of screw dislocations was found to increase and attained values comparable to that of edge dislocations. The lattice parameters ($\textit{a}$ and $\textit{c}$) were obtained independently to determine the in-plane and out-of-plane components of strain in films, which were analyzed to deduce the hydrostatic and biaxial strain contributions. The film grown at 100% N$_2$ displayed large micro-strain and hydrostatic strain due to excess/interstitial nitrogen, both of which decreased with the initial reduction of N$_2$ percentage, but increased again below 30% N$_2$ due to Ar incorporation. The films grown above 75% N$_2$ displayed compressive biaxial stress, which is attributed to possible nitrogen incorporation into grain boundaries and tensile side of edge dislocations. The reversal of biaxial stress to tensile character in films grown below 75% N$_2$ is explained by the prevalence of in-plane tensile stress generated during coalescence. The tensile stress decreased in films grown below 30% N$_2$, which is ascribed to the Ar incorporation and voided morphology. The presence of Si in the films does not have a significant influence on strain behaviour and appears to be masked by the dominant growth-related intrinsic effects.
