Highly selective etching methods for etching dielectric materials

摘要

Methods for forming high aspect ratio features using an etch process are provided. In one embodiment, a method for etching a dielectric layer to form features in the dielectric layer includes (a) supplying an etching gas mixture during a first mode to etch a portion of a dielectric layer disposed on a substrate while forming a passivation protection in the dielectric layer, wherein the dielectric layer is etched through openings defined in a patterned mask layer disposed on the dielectric layer, (b) supplying an etching gas mixture during a second mode to continue forming the passivation protection in the dielectric layer without etching the dielectric layer, and repeatedly performing (a) and (b) to form features in the dielectric layer until a surface of the substrate is exposed.

主权项

1. A method for etching a dielectric layer to form features in the dielectric layer, comprising:
(a) supplying an etching gas mixture in a first mode to etch a portion of a dielectric layer disposed on a substrate while forming a passivation protection in the dielectric layer, wherein the dielectric layer is etched through openings defined in a patterned mask layer disposed on the dielectric layer; (b) supplying the etching gas mixture in a second mode to continue forming the passivation protection in the dielectric layer without etching the dielectric layer, wherein the etching gas mixture include at least a silicon containing gas and a flow rate of the silicon containing gas supplied in the second mode is greater than a flow rate of the silicon containing gas supplied in the first mode; and (c) repeatedly performing (a) and (b) to form features in the dielectric layer until a surface of the substrate is exposed.