US 9,514,959 B2 · Fluorocarbon molecules for high aspect ratio oxide etch

Abstract

Etching gases are disclosed for plasma etching channel holes, gate trenches, staircase contacts, capacitor holes, contact holes, etc., in Si-containing layers on a substrate and plasma etching methods of using the same. The etching gases are trans-1,1,1,4,4,4-hexafluoro-2-butene; cis-1,1,1,4,4,4-hexafluoro-2-butene; hexafluoroisobutene; hexafluorocyclobutane (trans-1,1,2,2,3,4); pentafluorocyclobutane (1,1,2,2,3-); tetrafluorocyclobutane (1,1,2,2-); or hexafluorocyclobutane (cis-1,1,2,2,3,4). The etching gases may provide improved selectivity between the Si-containing layers and mask material, less damage to channel region, a straight vertical profile, and reduced bowing in pattern high aspect ratio structures.

Claims20

Dependent claims

A method for etching silicon-containing films, the method comprising,

introducing an etching gas into a plasma reaction chamber containing a silicon-containing film on a substrate, wherein the etching gas is selected from the group consisting of trans-1,1,1,4,4,4-hexafluoro-2-butene;
cis-1,1,1,4,4,4-hexafluoro-2-butene;
hexafluoroisobutene (CAS No. 382-10-5);
pentafluorocyclobutane (1,1,2,2,3-);
and tetrafluorocyclobutane (1,1,2,2-);
introducing an inert gas into the plasma reaction chamber;
and
activating a plasma to produce an activated etching gas capable of selectively etching the silicon-containing film from the substrate.

5 more elements

Dependencies are inferred from the claim text.

Fluorocarbon molecules for high aspect ratio oxide etch

Life of this patent

Fluorocarbon molecules for high aspect ratio oxide etch

Life of this patent

Abstract

Claims20