WORKING CHARACTERISTICS OF 2 MAGNETRON SPUTTERING DEVICES BASED ON DIFFERENT UNBALANCED MAGNETIC SYSTEMS OF TYPE-II

A comparison of the working characteristics of two similar planar d.c. magnetron sputtering devices that differ only in the geometry of the build-in magnetic assemblages is made. The comparative study includes the discharge characteristics of the two magnetrons for different pres sures of the sputtering gas Ar as well as some parameters characterisi ng the magnetron plasma in the area of the substrates. namely the self -bias electrical potential of the isolated substrate, the current towa rds the grounded substrate and the current to negatively biased substr ate. The values of the measured parameters and the character of the cu rves obtained show that both magnetron devices are of unbalanced type II. However, the expected strong advantages of the second magnetic sys tem, predicted in our previous investigation on the basis of the magne tic field distributions for the two assemblages, were not confirmed. T he experimental data obtained with 1-mm Cu target indicate that the ma gnetron sputtering source, using the first system. produces higher val ues of the floating potential, higher values of the current to the gro unded substrate and comparable values of the current to negatively bia sed substrates. These results. together with other advantages shown by the first system, namely the larger working range of the sputtering g as, lower running voltages, significantly larger efficiency of the tar get utilization and larger homogeneity of the thickness of the deposit ed films: determine the first system as being more appropriate for our future experiments on ion-assisted, thin-film deposition. (C) 1998 El sevier Science S.A.