Growth of Ru/RuO2 layers with atomic vapor deposition on plain wafers and into trench structures
Using beta-diketonate Ru precursors diluted in n-octane Ru and RuO2 layers were grown on plane 200nm SiO2/Si wafers by atomic vapor deposition (AVD). AVD was carried out in an AIXTRON Tricent system using liquid delivery of the ruthenium precursor. The deposited multi-crystalline smooth (RMS surface roughness <1nm) Ru layers are preferable orientated along the (002) plane and exhibit a near bulk sheet resistivity of around 10??cm for 20nm films with a uniformity better than 1.5%. By adding oxygen during the AVD process homogenous multi-crystalline RuO2 films are processed with a sheet resistivity of about 80??cm (for 30nm layer thickness) and uniformity better than 2%. Growth of Ru into trench structures is achieved by working with a pure Ru precursor in its kinetic growth regime. Highly conformal Ru thin films were deposited at 300C320C on trench structures. Depending on the deposition parameters like reactor pressure, injection frequency and opening time good Ru step coverage in trenches is achieved. More than 90% step coverage is obtained for structures with aspect ratios of 1:10.
atomic vapor deposition avd ruthenium ruthenium oxide metal gate stack