直流反应磁控溅射在氮化的蓝宝石衬底上制备AlN薄膜

通过直流磁控反应溅射装置,在蓝宝石(0001)衬底和氮化的蓝宝石(0001)衬底上成功制备了氮化铝(AIN)薄膜。利用X射线衍射仪、原子力学显微镜和双光束扫描分光计,研究了蓝宝石氮化对AIN薄膜结构、应力、晶粒尺寸、形貌和光学性质的影响。X射线衍射研究表明:制备的AIN薄膜具有较强的(0002)择优取向,蓝宝石衬底的氮化不仅能够改善AIN结晶质量,而且还可以减少薄膜的残余应力。但是,原子力学显微镜结果表明:在蓝宝石衬底上制备的AIN薄膜的晶粒大小分布比在氮化的蓝宝石衬底上制备的AIN薄膜的晶粒大小分布更加均匀。我们认为,蓝宝石衬底在氮化的过程中形成的AIN具有过多的位错和缺陷,正是这些位错和缺陷造成了在氮化的蓝宝石衬底上制备的AIN薄膜的晶粒大小分布的不均匀性。吸收光谱显示:蓝宝石衬底的氮化并没有对AIN薄膜的光学性质产生明显的改善。

Deposition of AlN Films on Nitrided Sapphire Substrates by Reactive DC Magnetron Sputtering

Aluminum nitride(AlN) films were prepared successfully on sapphire and nitrided sapphire substrates by reactive DC magnetron sputtering.The effect of nitridation of sapphire substrate on the growth of AlN films was studied.The films were characterized by X-ray diffraction(XRD),atomic force microscopy(AFM) and optical absorption spectrum.XRD patterns of AlN films exhibited a strong preferential c-axis orientation,and nitridation of sapphire substrate could improve the crystal quality of AlN films and also decrease the residual stress of films.But AFM results revealed that the grain size distribution of films deposited on nitrided sapphire substrates was not more homogenous than that of films deposited on sapphire substrates,and optical absorption results also showed nitridation of sapphire substrate nearly had no effect on the optical behavior of AlN films.