Characteristics of Tungsten Carbide Films Prepared by Plasma-Assisted ALD Using Bis(tert-butylimido)bis(dimethylamido)tungsten

Tungsten carbide thin films were prepared by plasma-assisted atomic layer deposition (ALD) using bis(tert-butylimido)bis(dimethylamido)tungsten at 250°C. The effects of plasma pulse time, radio frequency power, and the ratio on the film properties, such as resistivity, surface roughness, step coverage, and stability in air, were examined. The film growth rate (thickness/cycle) was in the range 0.04-0.07 nm/cycle and the resistivity of the films varied from 295 to 22,000 μΩ cm, depending on the plasma conditions. The films were smooth and the conformality of the films deposited in 0.15 μm holes with an aspect ratio of 15:1 was 100%.