Influence of negative bias voltage on structural and mechanical properties of nanocrystalline TiNx thin films treated in hot cathode arc discharge plasma system
Influence of negative bias voltage on structural and mechanical properties of nanocrystalline TiNx thin films treated in hot cathode arc discharge plasma system
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DOI：
10.1016/j.ceramint.2016.08.032
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发表时间：
2016-12
影响因子：
5.2
通讯作者：
O. Singh;H. Malik;R. P. Dahiya;Parmod Kumar
中科院分区：
文献类型：
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作者：
O. Singh;H. Malik;R. P. Dahiya;Parmod Kumar
采用直流溅射法在玻璃衬底上生长Ti薄膜，然后在热阴极电弧放电等离子体系统中氮化，这是一种独立监测等离子体和氮化参数的有效方法。原始Ti薄膜的硬度为~3.06 GPa，当负偏置电压增加到- 140 V时，硬度增加到~16.08 GPa，当负偏置电压增加到- 240 V时，硬度降低到~15.05 GPa。在晶粒尺寸和表面粗糙度方面也观察到类似的变化。晶粒尺寸从11.1 nm（原始Ti）增加到14.8 nm(−140 V)，然后减少到11.9 nm（−240 V）。表面粗糙度从2.78 nm（原始）增加到6.84 nm (-140 V)，发现-240 V时为4.14 nm。光学和电学测量也揭示了负偏置电压对薄膜带隙和电阻率的强烈影响。上述结果是基于低电压下氮离子的扩散和高电压下主晶格中氮离子的饱和来理解的。
Ti thin films were grown by DC sputtering on a glass substrate and then nitrided in a hot cathode arc discharge plasma system, which is an effective approach to independently monitoring the plasma and nitriding parameters. The hardness of pristine Ti thin film is found to be ~3.06 GPa, which increases upto ~16.08 GPa with an increase in negative bias voltage to −140 V and then decreases to ~15.05 GPa for higher of −240 V bias voltage. Similar kind of variation has been observed in crystallite size and surface roughness. Crystallite size is found to increase from 11.1 nm (pristine Ti) to 14.8 nm (for −140 V) and then reduces to 11.9 nm for –240 V. Surface roughness increases from 2.78 nm (pristine) to 6.84 nm (for –140 V), which is found to be 4.14 nm for –240 V. Optical and electrical measurements also reveal the strong impact of negative bias voltage on the bandgap and resistivity of the films. Above results are understood on the basis of diffusion of nitrogen ions for lower voltages and saturation of nitrogen ions in the host lattice for high voltages.