High rate deposition of Mgh hardness carbide thin films using a dual source dc magnetron sputtering method

反应溅射是用于沉积碳化物膜（例如TiC）的最有前途的技术之一，因为它允许在低温下在基底上存款碳化物涂层。反应溅射沉积碳化物薄膜时，通常采用Ar和碳氢化合物混合气体溅射纯金属靶。在这种情况下，沉积速率不应如此高，因为低溅射产率碳化物形成在靶表面上。由于所谓的滞后问题，膜组成的控制也是困难的。如果用固体碳靶作为沉积碳化物膜的碳源，这些缺点就可以消除。在本研究中，我们尝试以双源磁控溅镀法来沉积存款TiC薄膜。此外，Ti/C、TiC/C和TiC/Ti多层膜也作为先进的硬质涂层进行了研究。首先，确定了双源磁控溅射法制备化学计量比TiC薄膜的工艺条件。然后采用交替溅射法在玻璃基片上沉积了不同周期的Ti/C、TiC/C和TiC/Ti多层膜。可以实现周期小于1.7nm的Ti/C和TiC/C多层结构。另一方面，周期小于2.6nm的TiC/Ti多层结构不能被证实。Ti/C多层膜的硬度随着周期的减小而迅速增加。TiC/Ti复合材料的硬度随其周期的减小而单调增加。相反，TiC/C膜的硬度随着周期的减小而降低，这是由于微裂纹的产生。在这些多层结构中，TiC/C膜在真空中表现出最高的热稳定性。在空气气氛中，TiC/Ti薄膜的稳定性最高。这应该是纯碳层在600 ℃以上不稳定造成的。

Reactive sputtering is one of the most promising techniques for depositing carbide films, such as TiC, because it allows to deposit carbide coatings on the substrate at a low temperature. For depositing the carbide films by means of reactive sputtering, a pure metal target is usually sputtered by Ar and hydrocarbon mixed gas. In this case, the deposition rate should not be so high since the low-sputter-yield carbide is formed on the target surface. Control of the film composition is also difficult because of the so-called hysteresis problem. If the solid carbon target can be used as a carbon source for depositing carbide films, these disadvantages should be dispelled. In this study, we have tried to deposit TiC films by a dual source magnetron sputtering method. Furthermore, the Ti/C, TiC/C and TiC/Ti multilayer films have also been investigated as advanced hard coatings.Firstly, we have determined the deposition conditions for depositing stoichiometric TiC films by dual source magnetron sputtering. Then, Ti/C, TiC/C and TiC/Ti multilayer films with various periods were deposited onto glass substrates by an alternative sputtering. Ti/C and TiC/C multilayer structures, of which periods were shorter than 1.7nm, can be realized. On the other hand, TiC/Ti multilayer structure with the period less than 2.6nm can not be confirmed. The hardness of Ti/C multilayer films increases rapidly as the period decreases less than 2nm. The hardness of TiC/Ti increases monotonically with decreasing its period. On the contrary, the hardness of TiC/C films decreases as the period decreases because of micro-cracking. Among these multilayer structures, TiC/C films showed the highest thermal stability in vacuum. In the air atmosphere, on the contrary, TiC/Ti films revealed the highest stability. This should be caused by the instability of the pure carbon layer at above 600°C.