Effect of annealing conditions on the microstructure of RuO₂ thin films deposited by metalorganic chemical vapor deposition

Abstract

Ruthenium dioxide thin films were deposited on SiO₂/Si substrate at low temperatures by hot-wall metalorganic chemical vapor deposition using the ruthenocene and oxygen gas mixtures.

The RuO₂ films annealed at 700°C in 1 atm. oxygen ambient showed a dense and improved microstructure. However, above 750°C evaporation of RuO₂ was observed at the interface between RuO₂ and SiO₂/Si substrates as well as the surface of RuO₂ films. RuO₂ annealed at vacuum ambient(about 1.0 × 10⁻⁵ torr) of 500°C were partially reduced to Ru and completely Ru at 700°C. Films annealed at vacuum ambient showed the most low resistivity because RuO₂ was reduced to the Ru metal with increasing annealing temperatures. Films annealed in oxygen atmosphere of 600°C after vacuum annealing showed an uniform RuOx grain size but a little porous structure.

Key Words:

• Ruthenium dioxide
• Resistivity