Methods for cyclically etching a metal layer for an interconnection structure for semiconductor applications

A method of patterning a metal layer on a substrate, comprising:

• (a) performing an etching process using a hydro-carbon plasma to etch a metal layer disposed on a substrate in a processing chamber;
• (b) performing an ashing process using a hydrogen plasma on the metal layer;
• and
• (c) performing a sputter cleaning process using Ar gas or He gas on the metal layer;
• and
• performing (a) and (b) repeatedly or (a) to (c) repeatedly until desired features are formed in the metal layer.

A method of patterning a metal layer on a substrate, comprising:

• supplying an etching gas mixture including methane (CH4) and hydrogen (H2) gas to a processing chamber having a substrate disposed therein, the substrate having a metal layer disposed thereon;
• etching a portion of the metal layer from the substrate;
• exposing the metal layer to an ashing gas mixture comprising the hydrogen gas to the substrate;
• removing etching byproducts from the substrate;
• cyclically supplying the etching gas mixture and the ashing gas mixture to the processing chamber until desired features are formed in the metal layer;
• and
• supplying a sputter cleaning gas mixture including a He gas to sputter etch residuals from the substrate.