2.45 GHz Microwave Plasma Source Arrays for Large Area Deposition, Etch, and Surface Modification

New elementary microwave plasma sources provide large-scale substrate modification and film deposition capabilities with high density, uniform plasmas. While microwave plasmas have long been recognized as advantageous for coatings, etching, and surface modifications, they have also been recognized as limited in scalability and problematic in process robustness. Our solution to meeting the demands of large area plasma processing has been the development of elemental plasma sources, each powered by its own microwave solid state generator operating with variable frequency from 2.4 GHz to 2.5 GHz. Multiple plasma sources can be distributed in the same chamber, each source being controlled independently, adjustable in 1 watt increments from a few watts to 600 watts, and maintaining low reflected power without the use of impedance matching networks. The elemental sources have been designed in two configurations: an ECR plasma operable from 10^-2 Pa to a few Pa and collisional plasma operable from 1-100 Pa.

We present here results demonstrating plasma density and uniformity for various source arrays. Additionally, we present results on thin film depositions including SiO₂ and DLC, etching, and surface energy modification of polymer substrates.