Method for manufacturing three-dimensional nand flash memory array

Abstract

According to one embodiment of the present invention, a method for manufacturing a three-dimensional NAND flash memory array may include a polygate forming step of alternately stacking gates and gate insulating on a substrate to form a polygate; an opening forming step of forming an opening in the polygate; a polysilicon forming step of depositing silicon and an oxide filler into the opening to form a polysilicon; a metal film forming step of injecting metal into the polysilicon to form a metal film along a sidewall of the polysilicon; a crystal phase transition and growth step of irradiating a first microwave to the opening to grow crystalline silicon between the metal film and the polysilicon; and a crystal phase expansion step of irradiating a second microwave to the opening to expand the crystalline silicon toward a bottom surface of the opening.

Dependencies are inferred from the claim text.