ATC SERIES SPUTTERING SYSTEMS

The ATC Series Thin Film Deposition Systems feature dished top and bottom flanges with individual ports to accommodate deposition sources and substrate holders. Systems can be configured for con-focal, direct, and off-axis deposition. Con-focal deposition with in-situ tilt compatible sputter sources (AJA pioneered and developed this deposition concept in 1991) can deliver uniformity of better than +/- 2% on substrates twice the diameter of the targets. Often +/- 1% or better is achievable. A typical deposition profile with SiO(2) on a 6" diameter Si wafer is shown below.

Sputter deposition rate is a function of sputter yield of the material, maximum allowable power density into the target (depends on heat transfer capability of target material), and type of power used (eg. RF, DC, pulsed DC).

Maximum deposition rates are achieved with materials such as Au - high sputter yield, excellent heat transfer properties and it can be sputtered with DC (most efficient). Slow deposition rates can be expected with materials such as Al(2)O(3) - very low sputter yield, poor heat transfer properties and, being non-conductive, it must be sputtered with RF (1/2 the efficiency of DC). Typical rates are 0 - 18 A /sec with Au, 0 - 9 A/sec with Cu and 0 - 0.16 A/sec with Al(2)O(3). Off-axis deposition rates are typically 1-5 times lower than con-focal deposition rates depending on substrate size and system configuration. Direct deposition at short working distances can achieve much higher higher rates such as 300 A /sec for Au.

The ultimate configuration will depend on the application but if extremely high deposition rates are not required, con-focal geometry offers optimum results with the best uniformity, the ability to co-deposit alloy films and the ability to grow better ultra-thin film multilayers since the substrate is always "in the plasma".