Selective area growth of cubic group III-Nitrides on nano-patterned 3C-SiC (001) substrates

该项目的目的是在降低位错密度的预图案化3C-SiC（001）衬底上生长立方族iii -氮化物。利用电子束光刻（EBL）和反应离子蚀刻（RIE），在衬底上蚀刻出尺寸为50 nm的v形和u形沟槽或通过介电掩模。通过分子束外延（MBE），可以选择性地在纳米尺度的凹槽和开口上生长AlN和GaN。如果纳米结构具有较高的长径比（深度与宽度之比>>1），则在开口或凹槽内会发生有效的位错过滤，并且在立方族III氮化物中位错密度会降低几个数量级。采用高分辨率TEM、AFM、HRXRD、拉曼光谱、阴极发光和微光致发光等手段对立方族iii -氮化物进行表征。此外，在适当选择开口距离的结构下，将研究立方氮化镓薄膜的聚结。

The aim of the project is the growth of cubic group III-Nitrides on pre-patterned 3C-SiC (001) substrates with reduced dislocation density. Using e-beam lithography (EBL) and reactive ion-etching (RIE) V-shaped and U-shaped grooves with dimensions in the 50 nm scale will be etched into the substrate or through dielectric masks. The grooves and openings with dimensions in the nanometer scale will be selectively overgrown with AlN and GaN via molecular beam epitaxy (MBE). If the nanostructures have a high aspect ratio (ratio depth to width >>1) an effective dislocation filtering shall occur within the openings or grooves and the dislocation density shall be reduced by several orders of magnitude in cubic group III Nitrides. The cubic group III-nitrides will be characterized by high resolution TEM, AFM, HRXRD, Raman, cathodoluminescence and micro-photoluminescence. In addition, the coalescence of cubic GaN epilayers will be studied on structures with suitable selection of the distances of the openings.