Method for etching a gold metal layer using a titanium hardmask
AssigneeLam Research Corporation
InventorsGladys So-Wan Lo, David W. Mytton, Gregory James Goldspring
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Abstract
Disclosed is an inventive method for etching a gold metallization in a plasma processing chamber. The method includes introducing a substrate having a gold layer and an overlying titanium hardmask layer into the plasma processing chamber. The hardmask is first etched using conventional etching techniques. Then a plasma is formed in the chamber from an oxidizing gas and an etching gas. The etching gas is preferably a hydrochloric acid containing gas which may contain a chlorine containing gas. In addition, N2 may be provided. The plasma is then used to etch the gold layer through the TiN or TiW hardmask.
Claims12
A method for anisotropically etching a gold layer through an aperture in a hardmask, comprising:
- introducing a substrate into a processing chamber, said substrate including a gold layer, a hardmask layer disposed above said gold layer, wherein said hardmask layer is formed of a compound selected from the group consisting of TiN and TiW, and a patterned photoresist mask disposed above said hardmask layer;
- etching said hardmask layer through said photoresist mask, whereby at least one aperture is created in said hardmask layer to create a hardmask;
- and
- creating a plasma within said chamber from an oxidizing gas and an etching gas comprising hydrogen chloride, whereby said gold layer is etched through said aperture said hardmask.
A method for making an integrated circuit structure having a gold layer provided with a via, comprising:
- introducing a substrate into a processing chamber, said substrate including a gold layer, a hardmask layer disposed above said gold layer, wherein said hardmask layer is formed of a compound selected from the group consisting of TiN and TiW, and a patterned photoresist mask disposed above said hardmask layer;
- etching said hardmask layer through said photoresist mask, whereby at least one aperture is created in said hardmask layer to create a hardmask;
- creating a plasma within said chamber from an oxidizing gas and an etching gas comprising hydrogen chloride, whereby said gold layer is etched through said aperture in said hardmask;
- and
- processing said substrate though a series of semiconductor processes to form an integrated circuit.
Dependencies are inferred from the claim text.