US Patent 10032935 Semiconductor memory device with charge-diffusion-less transistors

A semiconductor memory device includes a substrate, a multi-layered structure including a plurality of insulating layers and a plurality of conductive layers that are alternately formed above the substrate, and a pillar extending through the multi-layered structure. The pillar includes a semiconductor body extending along the pillar, and a charge-storing film around the semiconductor body, the charge-storing film having a first thickness at first portions facing the insulating layers and a second thickness greater than the first thickness at second portions facing the conductive layers.