US Patent 12027374 Processes to deposit amorphous-silicon etch protection liner

Embodiments of the present disclosure generally relate to fabricating electronic devices, such as memory devices. In one or more embodiments, a method for forming a device includes forming a film stack on a substrate, where the film stack contains a plurality of alternating layers of oxide layers and nitride layers and has a stack thickness, and etching the film stack to a first depth to form a plurality of openings between a plurality of structures. The method includes depositing an etch protection liner containing amorphous-silicon on the sidewalls and the bottoms of the structures, removing the etch protection liner from at least the bottoms of the openings, forming a plurality of holes by etching the film stack in the openings to further extend each bottom of the openings to a second depth of the hole, and removing the etch protection liner from the sidewalls.