US 6,784,110 B2 · Method of etching shaped features on a substrate

Abstract

In a method of etching a substrate, a substrate is provided in a process zone, the substrate having a pattern of features comprising dielectric covering semiconductor. In a first stage, an energized first etching gas is provided in the process zone, the energized first etching gas having a first selectivity of etching dielectric to semiconductor of at least about 1.8:1, wherein the dielectric is etched preferentially to the semiconductor to etch through the dielectric to at least partially expose the semiconductor. In a second stage, an energized second etching gas is provided in the process zone, the energized second etching gas having a second selectivity of etching dielectric to semiconductor of less than about 1:1.8, wherein the semiconductor is etched preferentially to the dielectric.

Claims29

Dependent claims

A substrate etching method comprising:

(a) providing a substrate in a process zone, the substrate having a pattern of features comprising dielectric covering semiconductor;
(b) in a first stage, providing in the process zone, an energized first etching gas having a first selectivity of etching dielectric to semiconductor of at least about 1.8:1, wherein the dielectric is etched preferentially to the semiconductor to etch through the dielectric to at least partially expose the semiconductor;
and
(c) in a second stage, providing in the process zone, an energized second etching gas having a second selectivity of etching dielectric to semiconductor of less than about 1:1.8, wherein the semiconductor is etched preferentially to the dielectric.

1 more element

A method of etching a substrate in a substrate processing chamber comprising an antenna and process electrodes, the method comprising:

(a) providing a substrate in the chamber, the substrate having a pattern of features, the features comprising a semiconductor mesa covered by a dielectric top wall and dielectric sidewalls,
(b) in a first etching stage, providing in the chamber, an energized first etching gas comprising a halogenated non-hydrogen-containing gas and a halogenated hydrogen-containing gas in a volumetric ratio selected to etch the dielectric top wall to expose the semiconductor mesa;
and
(c) in a second etching stage, providing in the chamber, an energized second etching gas comprising the halogenated non-hydrogen-containing gas and a chlorine-containing gas in a volumetric ratio selected to etch the semiconductor mesa and the dielectric sidewalls;
(d) in a third etching stage, providing a third etching gas in the chamber and applying a first bias RF power level to the process electrodes and a first source RF power level to the antenna, thereby energizing the third etching gas to further etch the semiconductor mesa and the dielectric sidewalls;
and
(e) in a fourth etching stage, providing an energized fourth etching gas in the chamber and applying a second bias RF power level to the process electrodes and a second source RF power level to the antenna, thereby energizing the second etching gas to etch the semiconductor mesa and a remaining portion of the dielectric sidewalls.

4 more elements

Dependencies are inferred from the claim text.

Method of etching shaped features on a substrate

Life of this patent

Method of etching shaped features on a substrate

Life of this patent

Abstract

Claims29