Growth of Copper(I) Nitride by ALD Using Copper(II) Hexafluoroacetylacetonate, Water, and Ammonia as Precursors

Films of copper(I) nitride were deposited by atomic layer deposition (ALD) using copper(II) hexafluoroacetylacetonate, water, and ammonia as precursors. Introduction of a water pulse in the ALD cycle was found to be crucial for initiating film growth on both amorphous Si O 2 and single-crystalline α - Al 2 O 3 ( 001 ) substrates. The water pulses generated an oxidic copper monolayer, which in a subsequent ammonia pulse was converted to the nitride. The films have been grown in the temperature range from 210 to 302 ° C . Phase pure films of Cu 3 N were obtained up to 265 ° C . At higher deposition temperatures such as 283 ° C , phase mixtures of Cu 3 N and Cu were obtained. For temperatures above 302 ° C films of only Cu were grown. Film growth rate was the same on the two different substrates. The films were randomly oriented on Si O 2 . Completely intact films were obtained at a thickness of 20 nm . The optical bandgap of the films was measured to be 1.6 eV .