Development of Planar Magnetron Sputtering System with Facing Targets

本研究利用平面磁控溅镀系统，以两个靶材倾斜相对的方式，制备氮化铝及氧化锌薄膜。研究了这些薄膜的一些性质，并研究了该溅射系统在溅射薄膜制备中的应用。首先，在AlN薄膜的制备中，证明了在N_2气氛中，即使在10^ Torr量级的气压下也能保持放电<-4>。所得AlN薄膜均为c轴取向（c轴垂直于衬底），且c轴取向程度较高。溅射过程稳定，在50 ℃的低温下也能制备出c轴取向的AlN薄膜。这些结果表明，该溅射系统是有效的薄膜制备。在10 μ Torr量级的气压下获得高度c轴取向的膜<-3>。然而，在低于1 × 10 - 4托的压力下<-3>，观察到膜劣化，例如c轴取向的降低、膜着色和膜剥离。从通过能量色散X射线光谱法的光学透射率和膜组成估计的结果来看，这些膜劣化与膜生长中过量的N原子有关。这被认为是由于在较低的气体压力下将N离子注入到膜中。还发现在衬底前面施加磁场对增加c轴取向度是有效的。在O^2气氛下溅射Zn靶制备ZnO薄膜时，应避免高能O^-和O原子的轰击，以获得高度c轴取向的ZnO薄膜。因此。在倾斜面对的靶系统中，靶的倾斜角度被限制在一定角度内。

In this investigation, planar magnetron sputtering system with obliquely facing two targets was constructed, and films of AlN and ZnO were prepared. Some properties of these films were investigated and the utility of this sputtering system at the sputtered film preparation was studied. At first, in AlN film preparations, it was demonstrated that discharge was maintained even at gas pressures of the order of 10^<-4> Torr in N_2 atmosphere. Obtained AIN films were all c-axis oriented(c-axis is normal to the substrate), and the degree of c-axis orientation was high. The sputtering was stable, and even at low gasubstrate temperature of 50ﾟC, c-axis oriented AlN films were prepared. These results showed that this sputtering system is effective in the film preparation. Highly c-axis oriented films were obtained at the gas pressures of the order of 10^<-3> Torr. However, at the pressures below 1X10^<-3> Torr, the film degradation such as the decrease of c-axis orientation, film coloring and film peeling were observed. from the results of optical transmittance and film composition estimation by energy-dispersion X-ray spectroscopy, these film degradation were related to the, excess of N atoms in the film growth. This is thought to be due to the implantation of N ions into the film at lower gas pressures. It was also found that application of magnetic field in front of the substrate is effective to increase the degree of c-axis orientation. This indicates that the exposure of AlN film to the plasma influences the film quality.In ZnO film preparation by the sputtering of Zn targets in O^2 gas, film bombardment by energetic O^- and O atoms should be avoided to obtain highly c-axis oriented ZnO films. Therefore. in, the obliquely facing target system, the inclination angle of the target is limited in a certain angle.