Triple patterning NAND flash memory with SOC

摘要

A NAND flash memory array is initially patterned by forming a plurality of sidewall spacers according along sides of patterned portions of material. The pattern of sidewall spacers is then used to form a second pattern of hard mask portions including first hard mask portions defined on both sides by sidewall spacers and second hard mask portions defined on only one side by sidewall spacers.

主权项

1. A method of forming a hard mask layer comprising:
forming a plurality of portions of material that have a lateral dimension D which is defined by a photolithographic process and which are separated by spaces having a lateral dimension equal to D; subsequently forming sidewall spacers along sides of the plurality of portions of material, gaps between neighboring sidewall spacers having a lateral dimension approximately equal to D/3; subsequently removing the plurality of portions of material to leave the sidewall spacers; subsequently transferring a pattern formed by the sidewall spacers to form a plurality of patterned portions of a transfer material; subsequently depositing a hard mask material on the plurality of patterned portions of transfer material; subsequently etching back the hard mask material to leave first hard mask portions filling gaps between patterned portions of transfer material and second hard mask portions that extend along patterned portions of transfer material on one side and are exposed on another side; and subsequently removing the plurality of patterned portions of transfer material.