| abstract |
A method of making a monolithic three dimensional NAND string includes forming a select gate layer of a third material over a major surface of a substrate, forming a stack of alternating first material and second material layers over the select gate layer, where the first material, the second material and the third material are different from each other, and etching the stack using a first etch chemistry to form at least one opening in the stack at least to the select gate layer, such that the select gate layer acts as an etch stop layer during the step of etching. |