Plasma-Enhanced Chemical Vapor Deposition of Copper

Abstract

Plasma enhanced copper chemical vapor deposition (CVD) using acetyl-acetonato copper as a source compound is investigated for VLSI metallization. Results show that electrical resistivity and film morphology are greatly dependent on substrate temperature, and that plasma enhancement results in smooth copper film formation. Hydrogen is essential for reducing oxygen and carbon incorporation of copper film. A smooth surface film of low electrical resistivity (1.8 µΩcm) is obtained by plasma-enhanced CVD with hydrogen carrier gas at the substrate temperatures between 200°C and 280°C. Investigation of the step coverage of the film results in the coverage of the trench being superior to that of the sputtering method.