Method to etch Cu/Ta/TaN selectively using dilute aqueous HF/HCI solution

Patent metadata

Field	Value
Publication number	US-9123785-B1
Application number	US-201414202268-A
Country	US
Kind code	B1
Filing date	Mar 10, 2014
Priority date	Mar 10, 2014
Publication date	Sep 1, 2015
Grant date	Sep 1, 2015

Abstract

Copper can be etched with selectivity to Ta/TaN barrier liner and SiC hardmask layers, for example, to reduce the potential copper contamination. The copper film can be recessed more than the liner to further enhance the protection. Wet etch solutions including a mixture of HF and HCl can be used for selective etching copper with respect to the liner material, for example, the copper film can be recessed between 2 and 3 nm, and the barrier liner film can be recessed between 1.5 and 2 nm.

First claim

What is claimed is:

1. A method comprising
providing a substrate;
forming a dielectric layer above the substrate;
forming a plurality of trenches in the dielectric layer;
forming a liner layer above the dielectric layer in the trenches, wherein the liner layer comprises at least one of Ta or TaN;
forming a copper layer above the liner layer, wherein the copper layer fills in the trenches;
planarizing the liner layer and the copper layer so that a portion of the liner lay…

Assignees

• Intermolecular Inc
• Globalfoundries Inc
• Intermolecular Inc

Inventors

• Duong Anh
• Ryan Errol Todd

Classifications

• H10P52/403

  Electricity · mapped topic

• H10P50/667

  Electricity · mapped topic

• H10W20/435

  Electricity · mapped topic

• H10W20/425

  Electricity · mapped topic

• H10W20/081

  Electricity · mapped topic