US Patent 7927967 Method for manufacturing semiconductor memory device

A method for manufacturing a semiconductor memory device, includes: forming a stacked unit above a semiconductor substrate; making a hole in the stacked unit to pass through electrode layers and insulating layers of the stacked unit; forming an insulating film on a side wall of the hole, the insulating film including a charge storage layer; forming a semiconductor layer in an interior of the hole to align in a stacking direction of the electrode layers and the insulating layers to form a memory string; making a trench in a portion of the stacked unit proximal to the memory string to pass through the electrode layers and the insulating layers; forming a metal film on a side wall of the trench; forming a cap film to cover the metal film and fill into the trench; performing heat treatment to form a compound on the side wall of the trench.