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采用等离子体辅助的分子束外延(MBE)方法制备了InAlN外延薄膜,探讨了InAlN材料In原子数分数和生长条件的关系,以及等效束流强度(BEP)对材料质量的影响。绘制了InAlN关于温度与In和Al BEP的生长相图,经过优化后生长了与GaN晶格匹配的InAlN外延薄膜。使用高分辨率透射电子显微镜、X射线衍射仪、原子力显微镜和阴极荧光光谱(CL)对制备的InAlN材料进行了测试和表征。结果表明,InAlN/GaN异质界面清晰,In_(0.18)Al_(0.82)N外延材料(002)面X射线衍射峰半高宽为263 arcsec,表面粗糙度仅为0.23 nm,CL发光波长为283 nm,弯曲系数为5.2 e V,根据CL图像估算的材料位错密度约为2×108cm-2。
InAlN epitaxial films were prepared by plasma assisted molecular beam epitaxy (MBE). The relationship between the In atomic number fraction and the growth conditions of InAlN and the effect of equivalent beam current (BEP) on the material quality were discussed. The InAlN growth phase diagram of temperature versus In and Al BEP was plotted and an InAlN epitaxial film lattice-matched to GaN was grown. The prepared InAlN materials were tested and characterized using high resolution transmission electron microscopy, X-ray diffractometry, atomic force microscopy and cathodic fluorescence spectrometry (CL). The results show that the InAlN / GaN heterojunction interface is clear. The X-ray diffraction peak of In_ (0.18) Al 0.82 N epitaxial material (002) has a FWHM of 263 arcsec, surface roughness of only 0.23 nm and CL emission wavelength of 283 nm, the bending coefficient is 5.2 eV, and the material dislocation density estimated from the CL image is about 2 × 10 8 cm -2.