Integrated Linear-processing Ion-beam Sputtering System Using a Meter-scale Ribbon-beam

Abstract

We present a system capable of performing linear PVD processing by DC ion beam sputtering, suitable for reactive or high-vacuum deposition of dielectrics, metals, or magnetic materials onto conductive, insulating, or magnetic substrates. This equipment can be installed on a single vacuum flange for mounting on a variety of vacuum systems, but linear flow systems are preferred. Our recently developed ion source can generate ribbon ion beams of high current and low divergence over a wide range of energies, but is optimized for about 1 to 5 keV, and high ion currents of up to 1A per meter breadth; breadths of several meters are possible. The current density is an order of magnitude higher than existing systems. Uniformity is intrinsically good and can be controlled in real-time. The ion source and the sputter target are mounted close to each other and to the target; the cross section of the equipment does not change as the equipment is scaled up to large dimensions. The ion beam impinges on the sputter target at the optimum angle and energy, in a field-free region, and in high vacuum. This combination of conditions is unique, and dramatically raises the sputter yield. Free choice of beam energy permits higher thermal efficiency. High vacuum means that the deposited atoms comprising the film retain the full energy of several eV that was produced in the sputtering process. The geometry further permits extremely simple and efficient jetting of reactive gases such as oxygen for the production of oxide films. The single broad-beam source has far higher current density and a far more compact layout than existing ion-beam sputtering systems, and can be installed in linear processing systems in a similar manner to linear magnetrons.