The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 23, 2025
Filed:
Oct. 18, 2022
Tokyo Electron Limited, Tokyo, JP;
Tokyo Electron Limited, Tokyo, JP;
Abstract
Embodiments of improved processes and methods that provide selective etching of silicon nitride are disclosed herein. More specifically, a cyclic, two-step dry etch process is provided to selectively etch silicon nitride layers formed on a substrate, while protecting oxide layers formed on the same substrate. The cyclic, two-step dry etch process sequentially exposes the substrate to: (1) a hydrogen plasma to modify exposed surfaces of the silicon nitride layer and the oxide layer to form a modified silicon nitride surface layer and a modified oxide surface layer, and (2) a halogen plasma to selectively etch silicon nitride by removing the modified silicon nitride surface layer without removing the modified oxide surface layer. The oxide layer is protected from etching during the removal step (i.e., step 2) by creating a crystallized water layer on the oxide layer during the surface modification step (i.e., step 1).