Plasma processing method for substrates

Abstract

A substrate placement process uses a tray in which a plurality of substrate receiving holes are provided to receive substrates and which has substrate support portions protruding from inner walls of the substrate receiving holes. The tray is placed onto a tray support portion of a substrate stage and places substrates onto substrate holding portions, respectively, so that edge portions of the substrates projected beyond end edges of the substrate holding portions and are apart from the substrate support portions. The first plasma processing process reduces internal pressure of a chamber and supplies a process gas thereto to fulfill plasma processing for the individual substrates. A second plasma processing process with the tray and the individual substrates placed on the substrate stage, reduces the internal pressure of the chamber and supplies a process gas to fulfill plasma processing so that by-products stuck to edge portions of the substrates and the substrate support portions due to the first plasma processing process are removed. By the removal of by-products stuck to the edge portions of the substrates and the tray during plasma processing, product quality is improved.