Development of highly reactive high-density plasma sputtering process with excitation of helicon wave for synthesis of superhard nitride films

研究了利用m=0模式螺旋天线产生的螺旋波激发氮等离子体，该天线是为反应溅射合成超硬氮化膜而设计的。氮气在m Torr范围内获得的等离子体密度为1012 ~ 1013 cm-3。利用螺旋波激发高密度氮等离子体对碳靶进行反应溅射，制备了氮化碳薄膜。结果表明，在等离子体密度高达lx1012 cm-3的条件下沉积的CN膜的N/C比达到了~ 1.3。发现等离子体密度的增加和/或原子氮与底物附近分子带的发射强度比的增加直接影响了CN膜中的N/C组成比。傅里叶变换红外光谱的结构分析表明，在薄膜生长过程中，通过提高材料温度而不是强烈的紫外光照射，可以有效地消除与氢杂质有关的键。纳米压痕测试表明，该材料的硬度值高达~ 20gpa。我们还研究了等离子溅射内部型天线的射频电路结构和放电特性。在浮动天线状态下，满足阻抗平衡条件时，天线导体的射频电压幅值最小为天线端电压的1/2。此外，还通过离子轰击工艺研究了应力松弛对超硬氮化膜的增强作用。缓冲层的摩擦学和结构表征表明，缓冲层的控制对应力松弛是有效的，然而，cBN的红外to声子模式的峰移表明，在离子轰击生长的超硬膜中，压缩应变随着膜厚度的增加而积累是不可避免的。少

We performed investigations on the helicon-wave excited nitrogen plasmas generated using the m=0 mode helical antenna, which was designed for the reactive sputter synthesis of superhard nitride films. The achieved plasma density in m Torr range of nitrogen gas was measured to be 1012〜1013 cm-3. Carbon nitride films were deposited by the reactive sputtering of carbon target with the helicon waveexcited high-density nitrogen plasmas. Compositional characterizations of the CN films showed that the N/C ratio of〜1.3 was achieved by depositing the CN films at plasma densities as high as lx1012 cm-3. Increase in the plasma density and/or the emission-intensity ratio of the atomic nitrogen to the molecular band in the vicinity of the substrate was found to directly contribute to the N/C composition ratio in the CN films. Structural analysis by Fourier transform infrared spectroscopy showed that the bonds associated with hydrogen impurity could be effectively eliminated by increasing the substr … More ate temperature rather than intense UV light irradiation during film growth. Nanoindentation measurements showed that the hardness values of as high as 〜20 GPa was attained. We also performed investigations on the RF circuit configurations and the discharge characteristics of internal type antennas for plasma sputtering. The RF voltage amplitude of the antenna conductor was shown to be minimized to 1/2 of the antenna terminal voltage when the impedance balance condition was met in the floating antenna regime. Furthermore, materials investigations on the stress relaxation for enhancement of the superhard nitride films were additionally performed by ion bombardment processes. Tribological and structural characterizations of the buffer layer indicated that the buffer layer control can be effective for stress relaxation, however, the peak shifts of the IR TO-phonon mode of cBN indicated the accumulation of the compressive strain with increasing film thickness could not be avoided in the superhard film growth using ion bombardment. Less