SPUTTERING SYSTEMS WITH MAGNETICALLY ENHANCED IONIZATION FOR ION PLATING OF TIN FILMS

The reactive sputtering of hard coatings as TiN in large distances and/or on large substrates is difficult to perform with the conventional magnetron. A strong magnetic confinement of plasma between the magnetron target and substrates enhances the gas ionization and raises the ion current Isextracted to substrates. A new sputtering system with a multipolar magnetic plasma confinement (MMPC) is described. It consists of a planar unbalanced magnetron (UM), with diameter 120 mm equipped with two magnetic coils, and coupled to a closed multipolar magnetic field formed by a set of permanent magnets located on the internal surfaces of the deposition chamber, Typical operation characteristics of the new sputtering system are presented. It can be operated in a wide range of pressure from 5 to 0.02 Pa. The influence of different magnetic field configurations on Isand on the floating potential Un of substrates is also reported and compared with the characteristics of the UM without the multipolar field. Operation characteristics favorable for ion plating are observed. Ion current, densities ison substrates exceed 2 mA/cm2 even at negative bias Usbelow 60 V and on substrates placed in large distances as 200 mm from the target. The floating potential Unof substrates ranges from — 5 to — 50 V. Under these conditions are deposited dense golden TiN films with stresses as low as 2 to 3 GPa. © 1990, American Vacuum Society. All rights reserved.