A method of forming a
metal layer having excellent thermal and
oxidation resistant characteristics using
atomic layer deposition is provided. The
metal layer includes a reactive
metal (A), an element (B) for the amorphous combination between the reactive metal (A) and
nitrogen (N), and
nitrogen (N). The reactive metal (A) may be
titanium (Ti),
tantalum (Ta),
tungsten (W),
zirconium (Zr),
hafnium (Hf),
molybdenum (Mo) or
niobium (Nb). The amorphous combination element (B) may be aluminum (Al),
silicon (Si) or
boron (B). The metal layer is formed by alternately injecting pulsed source gases for the elements (A, B and N) into a chamber according to
atomic layer deposition to thereby alternately stack atomic
layers. Accordingly, the composition ratio of a
nitrogen compound (A-B-N) of the metal layer can be desirably adjusted just by appropriately determining the number of injection pulses of each source gas. According to the composition ratio, a desirable electrical
conductivity and resistance of the metal layer can be accurately obtained. The atomic
layers are individually deposited, thereby realizing excellent step coverage even in a complex and compact region. A metal layer formed by
atomic layer deposition can be employed as a barrier metal layer, a lower
electrode or an upper
electrode in a
semiconductor device.