Patent GB-1318141-A (GB)
Title: Sputtering apparatus
IPC: C23C14/34
Filed: 1971-01-04
Abstract: 1318141 Sputtering apparatus INTERNATIONAL BUSINESS MACHINES CORP 4 Jan 1971[22 Jan 1970] 262/71 Heading C7F An R. F. sputtering apparatus has an anode 11 spaced from and surrounding a target 14, and a cathode 12 spaced from and surrounded by the target to shield the cathode at least in the region in which sputtering is to take place. In a first embodiment, Fig. 1A, a cylindrical copper cathode 12 is surrounded by a cylindrical quartz or other dielectric target 14 which is surrounded by a cylindrical anode 11, the space 65 between target 14 and anode 11 forming a sputtering chamber and the space between cathode 12 and target 14 which is evacuated or filled with a liquid metal e. g. gallium being small so that, by capacitive coupling, a RF voltage applied from a source 30 to the cathode 12 is effective at the outer surface of the target 14. A cylindrical basket 118 of stainless steel or aluminium fits inside the anode 11 and supports substrates 126, Figs. 2-4 (not shown). Dielectric or metal members 25, 49, 90, 91, sealing rings and spacing members above and below the chamber 65 are provided, the member 91 beingraisable on support 101 into a removable upper sealed chamber 94, Fig. 1B (not shown). A vacuum pump is provided for this chamber and an atmosphere of argon may be introduced into chamber 65 by opening valve 81. Coils 133 enable an magnetic field to be applied. The cathode is cooled and thereby also the target through radiation by coolant fluid being pumped up a tube 27, through openings 23 around the inside surface of the cathode 12, through openings 25, down annular passage way 26 and out through opening 29. The anode 11 is cooled by a counter flow arrangement wherein fluid is passed in one direction through spiral tubes 73 and in the other direction through the spiral space between portions of the tubes 73. Initial ionisation within chamber 65 is obtained by energizing a wire 133. In a modified embodiment, Fig. 5 (not shown) the cathode and target are formed with a passage therebetween for the coolant which is a dielectric (e.g. deionised water) to effect electric as well as heat energy transfer and the anode coolant is water. Inflatable plastic seals may be used, Fig. 6, (not shown) and the RF voltage may be applied to both ends of the cathode assembly, Fig. 8 (not shown). In a continuous sputtering arrangement, Figs. 9-11 (not shown) the apparatus is disposed horizontally and substrates enter at one end and leave at the other after rotation of the anode. An automatic feed arrangement feeds substrate carriers 310 through a vacuum lock device and vacuum chambers, into longitudinal slots in the anode and after sputtering through further chambers to a further vacuum lock device. More than one such feed arrangement may be provided and substrates may remain in the sputtering chamber for example for 120 degrees, 240 degrees, 360 degrees or more of rotation of the anode. Liquid metal (gallium) or metallic paste may be applied to the back of the substrate carriers and metal targets are referred to. The cylindrical cathode, target and anode could be replaced by polygonal (e.g. triangular) members. The target may be mounted on the cathode by resilient fingers to transfer heat and RF energy. The substrates may be oscillated to give uniform deposits on large substrates.