US 6,582,569 B1 · Process for sputtering copper in a self ionized plasma

Abstract

A DC magnetron sputter reactor for sputtering copper, its method of use, and shields and other parts promoting self-ionized plasma (SIP) sputtering, preferably at pressures below 5 milliTorr, preferably below 1 milliTorr. Also, a method of coating copper into a narrow and deep via or trench using SIP for a first copper layer. SIP is promoted by a small magnetron having poles of unequal magnetic strength and a high power applied to the target during sputtering. The SIP copper layer can act as a seed and nucleation layer for hole filling with conventional sputtering (PVD) or with electrochemical plating (ECP). For very high aspect-ratio holes, a copper seed layer is deposited by chemical vapor deposition (CVD) over the SIP copper nucleation layer, and PVD or ECP completes the hole filling. The copper seed layer may be deposited by a combination of SIP and high-density plasma sputtering. For very narrow holes, the CVD copper layer may fill the hole.

Claims21

Dependent claims

A method of sputter depositing copper onto a substrate, comprising the steps of:

providing a chamber having a target principally comprising copper spaced from a pedestal for holding a substrate to be sputter coated by a throw distance that is greater than 50% of a diameter of the substrate;
rotating a magnetron about the back of the target, said magnetron including an inner magnetic pole of one magnetic polarity surrounded by an outer magnetic pole of an opposite magnetic polarity, a magnetic flux of said outer pole being at least 50% larger than the magnetic flux of said inner pole;
after a plasma has been ignited in the chamber, pumping said chamber to a pressure of no more than 5 milliTorr;
and
applying at least 10 kW of DC power to said target normalized to a 200 mm wafer while said chamber is pumped to said pressure, to thereby sputter copper from said target onto said substrate.

2 more elements

Dependencies are inferred from the claim text.

Process for sputtering copper in a self ionized plasma

Life of this patent

Process for sputtering copper in a self ionized plasma

Life of this patent

Abstract

Claims21