US 2021/0242032 A1 · METAL-CONTAINING PASSIVATION FOR HIGH ASPECT RATIO ETCH

Abstract

Various embodiments herein relate to methods, apparatus, and systems for etching a feature in a substrate. Typically the feature is etched in a dielectric-containing stack. The etching process involves cyclically etching the feature and depositing a protective film on sidewalls of the partially etched feature. These stages are repeated until the feature reaches its final depth. The protective film may have a particular composition, for example including at least one of a tungsten carbonitride, a tungsten sulfide, tin, a tin-containing compound, molybdenum, a molybdenum-containing compound, a ruthenium carbonitride, a ruthenium sulfide, an aluminum carbonitride, an aluminum sulfide, zirconium, and a zirconium-containing compound. A number of optional steps may be taken including, for example, doping the mask layer, pre-treating the substrate prior to deposition, removing the protective film from the sidewalls, and oxidizing any remaining protective film.

Claims22

Dependent claims

A method of forming an etched feature in a dielectric-containing stack on a substrate, the method comprising:

(a) partially etching the feature in the dielectric-containing stack by exposing the substrate to a first plasma comprising an etching reactant;
(b) after (a), depositing a protective film on sidewalls of the feature, the protective film comprising at least one of a tungsten carbonitride, a tungsten sulfide, tin, a tin-containing compound, molybdenum, a molybdenum-containing compound, a ruthenium sulfide, an aluminum sulfide, zirconium, and a zirconium-containing compound;
and
(c) repeating (a)-(b) until the feature is etched to a final depth, wherein the protective film deposited in (b) substantially prevents lateral etch of the feature during (a), and wherein the feature has an aspect ratio of about 5 or greater at its final depth.

1 more element

An apparatus for forming an etched feature in a dielectric-containing stack on a semiconductor substrate, the apparatus comprising:

one or more reaction chambers, wherein at least one reaction chamber is designed or configured to perform etching, and wherein at least one reaction chamber is designed or configured to perform deposition, each reaction chamber comprising:
an inlet for introducing process gases to the reaction chamber, and
an outlet for removing material from the reaction chamber, and
a controller having instructions for causing:
(a) partially etching the feature in the dielectric-containing stack by exposing the substrate to a first plasma comprising an etching reactant, wherein (a) is performed in the reaction chamber designed or configured to perform etching;
(b) after (a), depositing a protective film on sidewalls of the feature, wherein the protective film comprises at least one of a tungsten carbonitride, a tungsten sulfide, tungsten oxide, tin oxide, tin, a tin-containing compound, molybdenum, and a molybdenum-containing compound, and wherein (b) is performed in the reaction chamber designed or configured to perform deposition;
and
(c) repeating (a)-(b) until the feature is etched to a final depth, wherein the protective film deposited in (b) substantially prevents lateral etch of the feature during (a), and wherein the feature has an aspect ratio of about 5 or greater at its final depth.

5 more elements

Dependencies are inferred from the claim text.

Metal-containing passivation for high aspect ratio etch

Life of this patent

Metal-containing passivation for high aspect ratio etch

Life of this patent

Abstract

Claims22