Selective Deposition of Ruthenium Films by Digital CVD

Abstract

A novel process for selective and conformal deposition of ruthenium thin films is demonstrated by a liquid‐source digital‐CVD technique using alternate exposures of Ru(THD)2COD and oxygen. The films are selectively deposited at 280–320 °C on the exposed area of hydroxyl‐terminated ALD‐HfO2 surfaces patterned with photoresist (Figure). In general, ruthenium films deposited are found to be dense and polycrystalline, have a typical resistivity of 20.6 μΩ cm, and exhibit a positive temperature coefficient of resistivity, indicating metallic‐type conduction through electrically continuous grains.