US Patent 11716856 Three-dimensional memory device and method

A memory cell includes patterning a first trench extending through a first conductive line, depositing a memory film along sidewalls and a bottom surface of the first trench, depositing a channel layer over the memory film, the channel layer extending along the sidewalls and the bottom surface of the first trench, depositing a first dielectric layer over and contacting the channel layer to fill the first trench, patterning a first opening, wherein patterning the first opening comprises etching the first dielectric layer, depositing a gate dielectric layer in the first opening, and depositing a gate electrode over the gate dielectric layer and in the first opening, the gate electrode being surrounded by the gate dielectric layer.