摘要 |
PROBLEM TO BE SOLVED: To provide a plasma processing method for a substrate, which can form convexoconcave structures with uniform heights, when performing plasma processing to a sapphire substrate to form the convexoconcave structures corresponding to a mask pattern thereon.SOLUTION: The plasma processing method includes: a substrate loading step of loading a plurality of sapphire substrates having mask patterns formed on surfaces thereof in a chamber with the substrates being stored in a tray at a plurality of substrate storage portions, and mounting the sapphire substrates respectively on a plurality of substrate holding portions; and a plasma processing step of subjecting each of the sapphire substrates to plasma processing while filling a space between the substrate holding portions and the sapphire substrates with He gas, and forming the convexoconcave structures corresponding to the mask patterns on each of the surfaces of the sapphire substrates. In the plasma processing step, the plasma processing is performed in a state that a pressure of He gas in the space in a central region of the sapphire substrate is lower than a pressure of He gas in a peripheral region. |