Method for forming metal film by ALD using beta-diketone metal complex

A method of forming a single-metal film on a substrate by plasma atomic layer deposition (ALD), comprising:

• (i) contacting a surface of a substrate with a β-diketone metal complex in a gas phase whereby molecules of the β-diketone metal complex are attached to the surface of the substrate;
• (ii) exposing the molecule-attached surface only to a nitrogen-hydrogen mixed plasma, thereby forming an atomic layer of the metal;
• and
• (iii) repeating steps (i) and (ii) for a next atomic layer on top of the atomic layer in step (ii), thereby accumulating the atomic layers to form the single-metal film which is a virtually pure metal layer having a purity of at least 99% on the substrate,
• wherein the nitrogen-hydrogen mixed plasma is produced by supplying a gas containing nitrogen and hydrogen, followed by applying RF power of 200 to 500 W having a frequency of 13.56 MHz to the gas,
• wherein the gas containing nitrogen and hydrogen is a mixture of nitrogen gas and hydrogen gas wherein a volumetric ratio of nitrogen gas to hydrogen gas is 5/100 to 50/100.