Abstract: Methods for fabricating a 3D NAND flash memory are disclosed. The method includes the steps of forming a hardmask pattern on the hardmask layer, and using the hardmask pattern to form apertures in the alternating layers by selectively plasma etching the alternating layers versus the hardmask layer using a hydrofluorocarbon etching gas selected from the group consisting of 1,1,1,3,3,3-hexafluoropropane (C3H2F6), 1,1,2,2,3,3-hexafluoropropane (iso-C3H2F6), 1,1,1,2,3,3,3-heptafluoropropane (C3HF7), and 1,1,1,2,2,3,3-heptafluoropropane (iso-C3HF7), wherein the first etching layer comprises a material different from that of the second etching layer.

Abstract: A method of an embodiment includes (i) a step of supplying a first gas to a chamber, wherein the first gas is perfiuorotetraglyme gas, and (ii) a step of generating plasma of a second gas for etching of a porous film in order to etch the porous film at the same time as the step of supplying a first gas or after the step of supplying a first gas. Partial pressure of the first gas in the chamber or pressure of the first gas in the chamber when only the first gas is supplied to the chamber is higher than critical pressure causing capillary condensation of the first gas in the porous film and is lower than saturated vapor pressure of the first gas at a temperature of the workpiece during execution of the step of supplying a first gas.

Abstract: A porous film sealing method and porous film sealing material are provided to seal an object to be sealed that has a porous film. The porous film sealing method of the present invention is characterized by including a first step that supplies a first material to a treatment vessel in which is stored an object to be treated that has a porous film, and the first material includes a non-aromatic fluorocarbon having 6 or more carbon atoms.

Abstract: Methods for fabricating a 3D NAND flash memory are disclosed. The method includes the steps of forming a hardmask pattern on the hardmask layer, and using the hardmask pattern to form apertures in the alternating layers by selectively plasma etching the alternating layers versus the hardmask layer using a hydrofluorocarbon etching gas selected from the group consisting of 1,1,1,3,3,3-hexafluoropropane (C3H2F6), 1,1,2,2,3,3-hexafluoropropane (iso-C3H2F6), 1,1,1,2,3,3,3-heptafluoropropane (C3HF7), and 1,1,1,2,2,3,3-heptafluoropropane (iso-C3HF7), wherein the first etching layer comprises a material different from that of the second etching layer.