Three-dimensional flash memory including middle metallization layer and manufacturing method thereof

Abstract

A three-dimensional flash memory including an intermediate wiring layer and a method of manufacturing the same are disclosed. According to an embodiment, a method of manufacturing a three-dimensional flash memory by using a back end process includes: forming a lower string in a first block, the first block including a sacrificial layer and an insulation layer which are formed to extend in a first direction and are alternately stacked; generating an inter-string insulation layer on the first block that has the lower string formed therein; etching at least a portion of the inter-string insulation layer to form at least one sacrificial film in a space where the at least a portion is etched; generating a second block on the inter-string insulation layer, where the at least one sacrificial film is formed, the second block including a sacrificial layer and an insulation layer which are formed to extend in the first direction and are alternately stacked; forming an upper string in the second block; etching the sacrificial layer included in the first block, the at least one sacrificial film, and the sacrificial layer included in the second block; and forming an electrode layer, which is to be used as at least one intermediate wiring layer, in a space where the at least one sacrificial film is etched, and an electrode layer, which is to be used as a word line, in a space where the sacrificial layer included in the first block is etched and a space where the sacrificial layer included in the second block is etched.