纳米压痕方法测量超薄钛薄膜弹性模量的研究

Study on Elastic Modulus of Ultra-thin Ti Films Measured by Nanoindentation Method

利用直流磁控溅射(DCMS)在(100)方向的硅片上沉积厚度为60、90、120、180nm的钛薄膜。采用布鲁克原子力显微镜(AFM)以及扫描电镜/扫描探针显微镜(SEM/SPM)联合测试系统分别对其进行纳米压痕试验,并通过赫兹理论和King模型求得其弹性模量值。由布鲁克原子力显微镜(AFM)得到的结果表明,厚度为60~180nm的钛薄膜弹性模量在(95±2)GPa^(132±6)GPa;对于同一厚度的钛薄膜,在不同的峰值力下,其弹性模量均随着压入深度的增加而减小;而且对于不同厚度的钛薄膜,在相同的峰值力下,其弹性模量随薄膜厚度的增加而减小。另外,采用SEM/SPM联合测试系统得到钛薄膜的弹性模量同样随着薄膜厚度的增大而减小。

Ti nanofilm with the thickness of 60,90,120 and 180 nm was deposited on the (100) silicon wafer by using DCMS.The nano indentation experiments of the above nanofilm were carried out but by the AFM of Bruker and SEM/SPM combined system,respectively.Based on the Hertzian contact theory and King model,the elastic modulus was obtained.The results obtained by AFM of Bruker show that the elastic modulus of Ti films with the thicknesses of 60-180 nm is in the rang of (95±2 ) GPa-(132±6 )GPa.For the Ti film with the same thickness,under different peak forces,the elastic modulus decreases with the increase of the pressed depth.For the film with different thickness,under the same peak force,the elastic modulus of Ti films decreases with the increase of the film thickness.Furthermore,the elastic modulus of the film obtained by SEM/SPM combined system also decreases with the increase of the film thickness.