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通过XRD和Raman谱研究了用金属有机化学气相沉积 (MOCVD)的方法在Si( 111)面上生长的AlN薄膜层上的应力和压电极化 ,Raman谱观察到两个声子峰位分别在 619.5cm- 1 (A1 (TO) )和 668.5cm- 1 (E2 (high) )。通过光学声子E2 (high)的频移为 13cm- 1 计算得到AlN薄膜上的双轴压应力为 5 .1GPa ,在z轴方向上和在垂直于z轴方向上的应变分别为εzz=6 7× 10 - 3和εxx=-1 1× 10 - 2 ,产生的压电极化电荷PPE=2 .2 6× 10 - 2 c·m- 2 ,这相当于在Si的表面产生浓度为 1.41× 10 1 3c·cm- 2 的电子积累。同时 ,实验还发现在MOCVD生长过程中存在Si原子的扩散 ,在界面处形成了一个过渡层 ,过渡层主要以Si原子取代Al原子的位置并形成Si-N键为主。
The stress and piezoelectric polarization on the AlN thin film grown on the Si (111) surface by metal organic chemical vapor deposition (MOCVD) were studied by XRD and Raman spectroscopy. The two phonon peak positions were observed by Raman spectroscopy At 619.5 cm-1 (A1 (TO)) and 668.5 cm-1 (E2 (high)). The biaxial compressive stress on the AlN film was calculated to be 5.1GPa by the frequency shift of the optical phonon E2 (high) of 13cm-1. The strain in the z-axis direction and in the direction perpendicular to the z-axis are εzz = 6 7 × 10 -3 and εxx = -1 1 × 10 -2, resulting in a piezoelectric polarization charge of PPE = 2.2 × 10 -2 c · m -2, which corresponds to a concentration of 1.41 on the Si surface × 10 1 3c · cm -2 electron accumulation. At the same time, the experiment also found that during the growth of MOCVD, there exists diffusion of Si atoms, forming a transition layer at the interface. The transition layer mainly takes Si atoms instead of Al atoms and forms Si-N bonds.