The present invention generally comprises a method and apparatus for supplemental pumping, gas feed, and/or RF current for a process. When depositing amorphous silicon, the amount of process gases, RF current, and vacuum may be less than the amount of process gases, RF current, and vacuum necessary to deposit microcrystalline silicon. When a single chamber is used to deposit both amorphous and microcrystalline silicon, coupling a supplemental power supply, a supplemental gas source, and a supplemental vacuum pump to the chamber may be beneficial. The supplemental power supply, vacuum pump, and gas source, may be coupled with the chamber when the microcrystalline silicon is deposited and uncoupled when amorphous silicon is deposited. In a cluster tool arrangement, the supplemental power supply, vacuum pump, and gas source may serve multiple chambers that each deposit both amorphous and microcrystalline silicon.