Dynamic Reverse Pulsing Enhances Power System Performance

May 08, 2018 by Paul Shepard

Advanced Energy Industries, Inc. today announced Dynamic Reverse Pulsing™ (DRP), a power configuration technology that is marked by providing a higher deposition rate, lower substrate heating and higher power output on magnetrons. DRP's unique capabilities transform the paradigm in reactive sputtering and allow users to enable new processes and reap substantial cost savings.

Thin film coating professionals struggle with a variety of issues in reactive sputtering. These include the need to reduce process temperature for heat sensitive substrates; power level limitations due to heat, material and current; and anodes that "disappear" in high deposition rate configurations (DC).

DRP eliminates those pain points by lowering the heat and increasing the deposition rate, requiring fewer chambers, and increasing throughput of existing coaters without the expensive addition of cathodes, lids and zones.

"Advanced Energy's patented DRP technology offers customers an entirely new approach to delivering power in a sputtering coater," said Bruce Fries, general manager, AC-DC Products. "Innovation comes in the form of utilizing Ascent® DMS power supplies and a floating anode to deliver more net power to the cathodes with less heat on the substrate. This technology presents an unconventional power system configuration offering new economic benefits to our customers."

Recent data gathered from an Advanced Energy customer fully outlines the strong value in DRP. With an initial power system configuration of 40kHz ac, the customer reported a 4kW of total power, a deposition thickness of 230A and a heat load of 310C / 583K. However, when the power system was reconfigured to 40kHz DRP, the customer reported 4kW of total power per DMS, a deposition thickness of 380A and a heat load of 230C / 503K.

The new configuration translates into a 65 percent higher deposition rate and a 14 percent reduction in heat, resulting in a powerful improvement to processes and economic benefits.

This use case is just one of multiple that outlines benefits in using a DRP configured power system: one customer secured two times the deposition rate, and another customer secured a higher deposition rate at a lower heat load.

Additionally, in high volume consumer device coating, utilization of DRP-configured coaters can offer significant savings in capital investment, reducing the overall number of coaters needed for high volume production.

Reactive Sputtering

According to Angstrom Sciences, Inc.: Reactive sputtering is a process that allows compounds to be deposited by introducing a reactive gas (typically oxygen or nitrogen) into the plasma which is typically formed by an inert gas such as argon (most common), xenon, or krypton. In this process the reactive gas is "activated" by the plasma and chemically reacts with the surface of the sputtering target which is subsequently sputtered away.

By controlling the relative amounts of the inert and reactive gases, composition control of the resultant film is achievable. Oxides, nitrides, carbides and mixtures of all three are typically generated by reactive sputtering. The object of the reactive sputtering process is to create thin films of closely controlled stoichiometry and structure.