氮化硼薄膜内应力的红外光谱研究

Studies on the Stress in Cubic Boron Nitride Films by Infrared Spectroscopy

用射频（ＲＦ）磁控溅射制备了立方氮化硼（ｃ－ＢＮ）薄膜．ＦＴＩＲ光谱和电子衍射实验表明：该薄膜是纯的，其结晶度很高．ＦＴＩＲ光谱研究指出，基板负偏压是ｃ－ＢＮ相形成的重要因素，但也由此产生了ｃ－ＢＮ薄膜的应力，且负偏压越高，产生的应力越大．比较透射谱和反射谱的结果，ｃ－ＢＮ薄膜表面层的应力小于内部的．按照ｃ－ＢＮ形成的压力模型，表面应力小到一定程度可能影响ｃ－ＢＮ的继续生长．一个特制的分层结构ＢＮ薄膜保留了由于应力造成的ｃ－ＢＮ的裂纹，这个裂纹分布在一些同心圆上，中心是缺陷或杂质，同心圆之间有明显的分界线，把ｃ－ＢＮ表层分割成许多应力区．

A RF sputtering was used for preparing cubic boron nitride ( c BN) films. The results from infrared spectra and transmission electron diffraction show that a pure c BN film with a high crystallinity was obtained. The analyzing of IR spectra indicate that the negative substrate bias is an important condition, and also the reason to form the stress, the higher the bias, the higher the stress. Comparing the reflecting IR absorption spectra with the transmission IR absorption spectra, it is first found that the stress on the surface layer of c BN film is smaller than that in c BN film. In terms of its compressive stress mode of the growth of c BN should be limited by a very small stress on the surface layer of c BN film. A BN film with the layer built was specially prepared for investigating the distribution of the stress on the surface layer of c BN film. The cracks resulted from the stress of c BN film were first kept miraculousness. The arrangement of the cracks shows the distribution of the stress on the surface layer of c BN film at the horizontal direction.