Method and apparatus for atomic layer etching

An atomic layer etching method of etching an etching target film by sequentially performing a surface modification step and an etching step,

• wherein the surface modification step comprises:
• a surface modification layer formation step of forming a surface modification layer on a surface of the etching target film using radicals;
• and
• a precursor supply step of supplying a precursor to adsorb precursor molecules onto the surface of the etching target film having the surface modification layer formed thereon,
• wherein the etching step comprises:
• a heat treatment step of thermally treating a substrate having undergone the surface modification step to remove the surface modification layer from the etching target film;
• and
• a cooling step of cooling the thermally treated substrate, and
• wherein the surface modification step further comprises a plasma treatment step of treating the surface of the etching target film using ions in at least one of sections before the surface modification layer formation step and after the precursor supply step.

An atomic layer etching apparatus comprising:

• a first process chamber configured to perform plasma treatment on a surface of an etching target film to form a surface modification layer on the etching target film;
• and
• a controller operatively coupled to the first process chamber,
• wherein the first process chamber comprises:
• a chamber body having a processing space defined therein;
• a substrate support unit disposed inside the chamber body, the substrate support unit being configured to support a substrate having the etching target film formed thereon;
• a shower plate partitioning an internal space of the chamber body into an upper plasma generation space and a lower processing space, the shower plate including a plurality of through-holes, the shower plate being connected to ground;
• an upper plasma generation unit configured to generate plasma in the plasma generation space;
• a lower plasma generation unit configured to generate plasma in the processing space;
• and
• a gas supply unit configured to supply a gas to an interior of the chamber body, and
• wherein the controller is configured to perform:
• a first plasma treatment step of treating the surface of the etching target film using ions of a first gas by controlling the gas supply unit and the lower plasma generation unit to generate plasma of the first gas in the processing space;
• a second plasma treatment step of forming the surface modification layer on the surface of the etching target film using radicals of a second gas supplied to the processing space through the plurality of through-holes by controlling the gas supply unit and the upper plasma generation unit to generate plasma of the second gas in the plasma generation space;
• a precursor supply step of adsorbing precursor molecules onto the surface of the etching target film having the surface modification layer formed thereon by controlling the gas supply unit to supply a precursor to the processing space;
• and
• a third plasma treatment step of treating the surface of the etching target film having the surface modification layer formed thereon using ions of a third gas by controlling the gas supply unit and the lower plasma generation unit to generate plasma of the third gas in the processing space.