【摘要】 氮化铝(AlN)是一种重要的超宽禁带半导体材料。本文研究了采用氢化物气相外延(HVPE)方法生长氮化铝的表面形貌演化和生长机理。AlN的制备过程是氮化处理后以700～1 100℃的不同温度生长,得到四组不同温度下的表面形貌。结果表明,生长温度对AlN的生长形貌和生长模式具有重要的影响。AlN的生长形貌体现在纳米尺度和微米尺度的形貌差异,该结果归因于受生长温度主导的Al原子的表面迁移能力和位错演化。另外,在900℃生长温度下得到具有倒金字塔结构的V坑形貌。V坑面为{10-11}半极性面,并遵循三维(3D)生长模式。这种具有半极性面微观形貌的AlN可作为模板进行半极性紫外LED器件结构或其他Ⅲ族氮化物外延生长,在光电子器件和电子器件研制方面具有广阔的应用前景。更多还原

【Abstract】 Aluminum nitride( Al N) is a significant ultra-wide bandgap semiconductor material. This paper studies the surface morphology evolution and growth mechanism of Al N grown on sapphire substrates by hydride vapor phase epitaxy( HVPE). The morphologies of Al N are controlled by the nitridation pre-treatment and the growth temperature from 750 ℃ to 1 100 ℃ ． The results show that growth temperature played a critical role in the Al N growth of morphology and growth mode. The difference in nanoscale or microscale morphologies of Al N is attributed to the surface migration of Al adatoms dominated by the growth temperature and the evolution of the dislocation. Moreover,the surface morphology evolution leads to an inverted pyramid morphology or large V-shaped pits at the growth temperature of900 ℃ ． The grown V-shaped pits have {10-11 } semi-polar facets and follow the three-dimensional(3D) growth mode. The semi-polar facets Al N structure could be used for realizing facet-controlled epitaxial of semi-polar UV-LED or other Ⅲ-nitride growth,which has prospects in optoelectronic and electronic devices.更多还原