MAGNETRON SPUTTER COATING SOURCE FOR BOTH MAGNETIC AND NONMAGNETIC TARGET MATERIALS

摘要

-47-ABSTRACTMagnetron Sputter Coating Source for BothMagnetic and Nonmagnetic Target MaterialsA novel magnetron sputter coating source isdisclosed in which magnetic sputter targetscontaining relatively large inventories of usablematerial may be employed. This coating sourcemay also be used efficiently and effectively withsputter target materials having proerties whichrange from nonmagnetic to highly ferromagnetic. Useof an electromagnetic coil with a widely adjustableenergizing current, rather than permanent magnets,allows a wide range of magnetic properties to beaccommodated. Electrical impedance of the glowdischarge is readily controlled using the currentflow through the electromagntic coil, allowing,for example, operation at desired values of voltageand current throughout the life of the sputtertarget. In addition, a momentary increase inelectromagnet coil current can be used to achieveignition of the glow discharge at a desired sputtergas operating pressure which is below the sputtergas pressure at which the glow discharge can normallybe readily ignited. Also, use of the electromagneticcoil permits an easy conversion of the magnetronsputter coating source to a nonmagnetic diodeapparatus. The use of a Hall probe positionedadjacent and below the sputter target near theregion of maximum erosion is disclosed. The Hallprobe voltage, which is proportional to the magneticfield intensity at the Hall probe position, maybe measured throughout sputter target life toprovide an independent means of assessing theapproach to end of useful life. A novel sputter-48-target cooling means is disclosed in which a waterchamber below the sputter target is divided intoinlet and outlet portions by a septum. The flow ofwater through a narrow gap between the septum andthe sputter target leads to highly effective heattransfer, which is also highly uniform along theperipheral path of intense heating of the sputtertarget.