METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE AND ETCHING METHOD

A method of manufacturing a semiconductor device according to an embodiment includes: forming a multilayer structure in which first insulating layers and second insulating layers are alternately stacked; and forming a plurality of contact holes in the multilayer structure, each of the contract holes having a different aspect ratio, the forming of one of the plurality of contact holes including a first step of etching at least one of the first insulating layers and a second step of etching at least one of the second insulating layers, and the second step is performed by using a mixed gas including a CHF gas which contains carbon, hydrogen, and fluorine and hydrogen gas.