Paper TF-ThP37
Linear Scanning Magnetron for Solar Cell PVD Applications

Thursday, November 10, 2016, 6:00 pm, Room Hall D

In this presentation we discuss Linear Scanning Magnetic Array (LSMA) technology for magnetron sputtering in

conjunction with in-line substrate processing. In this approach, the magnet array (pole) scans over planar target

spreading the erosion pattern in a controlled fashion. Thus, high quality, dense metal films with good uniformity can be

produced at significant advantages over static magnetrons, such as significantly higher target utilization, longer

uptime, and prevention/removal of target defects related to re-deposition.

We review the influence of magnet motion acceleration/deceleration, the influence of endpoint motion offset

(stagger), and the influence of magnet - to - substrate velocity ratio, on target utilization and lead-to-trail edge film

uniformity. Trade-offs between uniformity and target utilization were established and characterized.

The optimization method we use employs a combination of theoretical simulations and experimental

measurements. Theoretical analysis utilizes ANSYS static magnetic field simulations, erosion profile calculations

including motion integration effects, and ray tracing method for sputtering film thickness calculations

(MATLAB). The structure and uniformity of LSMA-deposited thin films was characterized experimentally by

XRF, 4 point probe and SEM, and the target erosion measured by weight and erosion profiles of spent targets.

We have demonstrated that, with a judicious design approach, an optimal range of operating parameters can be

defined and target utilizations in 60-70% range can be reached, while maintaining deposition uniformity below 2% with

excellent film properties. This makes the LSMA plasma source (using planar targets) more economically

competitive than static and rotatable magnetrons.