Properties of AlN coatings produced by RF sputtering method

The development of insulating coatings is one of the most important subjects in fusion reactor liquid lithium blankets. AlN, Y2O3 and Er2O3 are thought to be good candidate materials for ceramic coatings because of their high electrical resistivity and high compatibility with liquid lithium. In this study, AlN coatings were fabricated by the RF sputtering method, and their properties were investigated. The coatings were similar to the composition rate by XPS analysis, and crystal grains grow as (1 0 0) face when the fabrication temperature became higher. Although deterioration of electrical resistivity was shown in all coatings, the coatings still have high resistivity. After annealing, the crystallinity of the coatings increased. After exposure in liquid lithium, almost all of the coatings were lost and only small fragments remained.