Patent ID: 9595451
Date: 2017-03-14
CPC Classifications: H01L

Claim:
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.