溅射功率对GeSb_2Te_4膜形貌及力学性能的影响

Effect of sputtering power on surface topography and mechanical properties of GeSb_2Te_4 phase-change films

利用电子回旋共振CVD设备的射频磁控溅射方法制备了GeSb2Te4膜,采用原子力显微镜、纳米硬度计以及侧向力显微镜考察了不同溅射功率对GeSb2Te4膜表面微观结构以及力学性能的影响.结果表明:在一定的溅射功率范围内,由于薄膜生长方式从三维向二维的转化,薄膜的表面粗糙度随功率的增大而降低,而且薄膜致密度也随之提高,从而使得非晶态GeSb2Te4膜硬度和弹性模量增大.利用能量密度理论对这一现象进行了分析.另外,由于表面能等因素的影响,功率为63W制备的GeSb2Te4膜粘附力较高,摩擦系数却较小.

GeSb2Te4 films were deposited by RF magnetron sputtering with electron cyclotron resonance microwave plasma chemical vapor deposition equipment （ ECR- CVD）. The effect of sputtering power on the surface topography and mechanical properties of the GeSb2Te4 films were studied with AFM/LFM and nanoindenter. The results indicate that with the increase of the sputtering power at certain power range the surface roughness decreases due to the growth mode variation from three dimensions to two dimensions, and the films＇ densification increases. Thereby, the mechanical properties such as hardness and elastic modulus are enhanced. Energy density theory is used to explain the reason why the mechanical properties of amorphous GeSb2Te4 films are affected by sputtering power. The GeSb2Te4 film deposited with sputtering power of 63 W presents higher adhesion, but its friction coefficient is relatively low due to greater hardness.