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硅基AlN应力和压电极化研究
Study on Strain and Piezoelectric Polarization of AlN/Si
【摘要】 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。
【Abstract】 The structural properties of AlN thin film grown on Si(111) substrate by metalorganic chemical vapor deposition (MOCVD) were investigated using X-ray diffraction and Raman measurements. Phonons at 619.5 cm-1(A1(TO)) and 668.5 cm-1(E2(high)) were found. The stress and piezoelectric polarization of the AlN film were analyzed with E2(high) phonon mode frequency shift in Raman spectra. The result indicates that the amount of the biaxial compressed stress is about 5.1 GPa, the strain along the z-axis and perpendicular to the z-axis was calculated i.e., εzz=6.7×10-3 and εxx=-1.1×10-2, respectively. The amount of the piezoelectric polarization is about 2.26×10-2 c·cm-2, equal to electrons with density of 1.41×1013 cm-2 on the surface of Si. Phonons of Si-N bonds were also observed accompanying phonons of AlN crystal in Raman spectra, which indicate that Si atoms diffuse into AlN layers during growing and form a transition layer at the interface of AlN/Si, and Si atoms take the place of Al atoms mostly and Si-N bonds are formed.
【Key words】 Raman spectra; stress; piezoelectric polarization; Si-N bonds;
- 【文献出处】 稀有金属 ,Chinese Journal of Rare Metals , 编辑部邮箱 ,2004年03期
- 【分类号】TN304.2
- 【被引频次】7
- 【下载频次】247