Development of high rate sputtering system for the deposition of transparent conductive thin films with low resistivity and high adhesion on plastic film substrate.

本研究发展了一种无损伤、高沉积速率的磁控溅射沉积方法，用于在塑料衬底上沉积低电阻率的透明导电薄膜。1）磁控溅射和对靶溅射中，等离子体电子的入射都是导致衬底加热的主要原因。从靶表面发射的高能二次电子的入射是衬底加热的其他来源之一。与磁控溅射系统相比，对靶溅射系统由于衬底处于无等离子体状态，因此入射的加热能量要低得多。2）抑制晶体生长是获得具有优异表面平整度的薄膜的必要条件。在ITO中加入少量的Zn可以有效地抑制薄膜的晶体生长。晶体生长的抑制也有效地降低了膜压应力，并且在约8mTorr的适当溅射气压下可以实现无应力膜。3）我们表明，具有相对靶布置的双阴极脉冲溅射对于在直流模式下实现稳定的氧化物膜的高速率溅射是有用的，并且通过将阳极电势保持在地电势，可以抑制等离子体中的带电粒子对衬底表面的轰击。4）发现ITO薄膜的电学性质随衬底位置的变化而发生显著变化，并阐明了这种薄膜的不均匀性主要是由来自靶表面的氧原子和In原子之间的发射角分布的差异引起的。

In this study, damage-less sputter-deposition method with high deposition rate have been developed for the deposition of transparent conductive thin films with low resistivity on a plastic substrate.1)The substrate heating during sputter-deposition was mainly caused by the incidence of electrons from the plasma in both magnetron sputtering and facing target sputtering. Incidence of high energy secondary electrons emitted from the target surface was one of the other sources for the substrate heating. Compared with the magnetron sputtering system, the amount of the incident heating energy was much lower in facing target sputtering system, since the substrate was kept in a plasma free condition.2)The suppression of crystal growth was necessary to obtain a film with excellent surface smoothness. The addition of small amount of Zn into ITO was effective to suppress the crystal growth of the film. The suppression of crystal growth was also effective to reduce the compressive film stress and stress free films can be realized at a proper sputtering gas pressure around 8 m Torr.3)We showed that pulse sputtering of dual cathodes with opposed target arrangement was useful to realize a stable high rate sputtering of oxide film in a dc mode, and bombardment of substrate surface by charged particles in plasma can be suppressed by keeping the anode potential at earth potential. We also showed that combination of facing targets sputtering source and magnetron source works effectively as a dual sputtering system.4)We found that the electrical properties of the ITO films changes significantly with substrate position, and clarified that this non-uniformity of the film is mainly caused by the differences in the distribution of emission angles between oxygen atoms and In atoms from the target surface.