PREPARATION OF EPITAXIALLY GROWN Cr-Si-N THIN FILMS BY PULSED LASER DEPOSITION

摘要

Cr-Si-N thin films having nanosized CrN crystallites with B1 (NaCl type) structure have higher hardness and tribological properties than those of CrN. It is thought that solubility of Si atoms in the CrN lattice with six coordination is limited, since Si is easy to form four coordination. However, whether Si is contained in the nanosized CrN crystal has not been clear. In this work, epitaxially grown Cr-Si-N thin films with Bl structure have deposited on MgO(100) substrates using pulsed laser deposition. The laser was focused on a rotating target that a Si wafer was attached on a Cr disk. The ratio of surface area of Si for Cr (Sr) is controlled. Nitrogen plasma from an RF radical source was introduced in the deposition chamber. The prepared thin films were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and electron energy loss spectroscopy. In these results, both samples of S_r = 0 and 10%, i.e. CrN and Cr-Si-N, have Bl structure and epitaxial grown on MgO substrate. The Si content in these thin films were 0 and 5.0 at.%. Hardness of CrN and Cr-Si-N measured by nanoindentation were 29 and 36 GPa, respectively.