Etch characteristics of maskless oxide/nitride/oxide/nitride (ONON) stacked structure using C₄H₂F₆-based gas.

ABSTRACT: Oxide/Nitride/Oxide/Nitride (ONON; SiO₂/SiN_x/SiO₂/SiN_x) stacked structure is widely used in the 3D vertical structure of semiconductor cells. Previously, to form a 3D cells, photoresist (PR) was patterned and repeatedly trimmed on the top of ONON after the etching of one ON layer. Due to the time-consuming process of etching layer-by-layer of ON layer, two-step etch processing using C₄F₈-based or C₄F₆-based gases composed of maskless ONON stack feature etching and followed one ON layer-by layer etching by PR trimming in the ONON stack feature are employed these days. However, the two-step etching method resulted in poor etch profiles of maskless ONON stack feature in addition to high global warming pote

SUBMITTER: Cho NI 

PROVIDER: S-EPMC11447234 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature