Multi-step process for depositing copper seed layer in a via

US6893541B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Tony P. Chiang · Campbell, US
• Yu D. Cong · Sunnyvale, US
• Peijun Ding · San Jose, US
• Jianming Fu · San Jose, US
• Howard H. Tang · San Jose, US
• Anish Tolia · San Jose, US

Key dates

• Filing date: Dec 20, 2002
• Grant date: May 17, 2005
• Expiry date: Dec 20, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2221/1089
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

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.