High throughput, high quality dry etching of copper/barrier film stacks

Dry etching of copper interconnect lines in a chlorine-based plasma has bee n investigated. Copper dry etching was carried out in a modified diode-type reactive ion etch (RIE) system and in an inductively coupled plasma (ICP) etch system. The ICP system offers a significant increase in copper etch ra te compared with the low-efficiency RIE system while maintaining excellent pattern transfer accuracy. A number of fundamental issues in high quality a nd high throughput copper dry etching will be discussed. Electrical charact erization of patterned copper lines with line width as small as 0.25 mu m i ndicates low electrical resistivity and good electromigration performance. (C) 2000 Elsevier Science B.V. All rights reserved.