Experimental demonstration of phase-toggled microwave surface wave plasma for large-area film deposition

Microwave surface wave plasma is known for its ability to produce high plasma density and temperature, enabling massive production of radicals. These features allow for faster processing time, making it a promising source for material processing. However, the short wavelength of microwaves inherently limits the uniform field distribution in large-scale chambers, and overcoming this limitation has been a significant challenge for practical applications. Our recent study revealed that using multiple microwave inputs and toggling their phase between 0 and π can enhance field uniformity inside the chamber, but the effectiveness of the method in plasma processing had not yet been demonstrated. Here, we present the first experimental demonstration of alumina (Al2O3) film deposition using the phase-toggling method in a large-diameter (450 mm) chamber.