ETCHING METHOD AND PLASMA PROCESSING APPARATUS

An etching method includes: (a) providing a substrate including a silicon-containing film on a substrate support; (b) adjusting a temperature of the substrate support to −20° C. or lower; (c) supplying a processing gas including a nitrogen-containing gas, into the chamber; (d) etching the silicon-containing film by using plasma generated from the processing gas. A recess is formed by etching the silicon-containing film, and a by-product containing silicon and nitrogen adheres to a side wall of the recess. The etching method further includes (e) setting at least one etching parameter of the temperature of the substrate support and the flow rate of the nitrogen-containing gas included in the processing gas, to adjust the width of the bottom of the recess according to an adhesion amount of the by-product, before (b).