DISCHARGE CHARACTERISTICS OF A FACING TARGET SPUTTERING DEVICE USING UNBALANCED MAGNETRONS

This article presents the details of our investigations on the charact eristics of a facing target sputter discharge using two highly efficie nt unbalanced magnetrons with electromagnetic coils. The variation of ignition and extinction pressures has been studied as a function of th e current in the coils (I-1 and I-2) in both the magnetrons at two int ertarget distances 290 and 125 mm, respectively. These studies have be en carried out in closed as well as cusp field configurations and the results are compared. A negative resistance region has been observed i n the discharge characteristic in the cusp field at longer intertarget distances (290 mm), which has been explained on the basis of electron trapping efficiency. Although the closed field has been found to be a dvantageous in achieving the lower pressure operation possible (0.01 P a), deposition rates are relatively higher (about 20%) in the cusp fie ld. (C) 1996 American Vacuum Society.