Abstract: A method for manufacturing a semiconductor device according to an embodiment is a method for manufacturing a semiconductor device including performing a first etching process of forming a recess in a layer to be processed formed on a substrate by reactive ion etching using a first gas, performing a first process of supplying hydrogen radicals to the recess by using a second gas containing hydrogen in a state where a temperature of the substrate is equal to or more than 200° C. and equal to or less than 350° C. after the first etching process, and performing a second etching process of etching a bottom surface of the recess by reactive ion etching using a third gas after the first process.

Abstract: A semiconductor device manufacturing apparatus according to an embodiment includes: a chamber; a holder provided in the chamber and capable of adsorbing a substrate, the holder including a recess on a surface, a first hole provided in the recess, and a second hole provided in the recess; a first gas passage connected to the first hole; a second gas passage connected to the second hole; a first valve provided in the first gas passage; a second valve provided in the second gas passage; a first gas supply pipe for supplying a first gas to the recess; and a gas discharge pipe for discharging a gas from the recess. The first gas passage and the second gas passage are connected to the first gas supply pipe, or the first gas passage and the second gas passage are connected to the gas discharge pipe.