Combinatorial chemical vapor deposition. Achieving compositional spreads of titanium, tin, and hafnium oxides by balancing reactor fluid dynamics and deposition kinetics

A low-pressure chemical vapor deposition (CVD) reactor was modified to produce a continuous compositional spread of titanium, tin, and hafnium dioxides on a single Si(100) wafer. The corresponding anhydrous metal nitrates, Ti(NO3)(4), Sn(NO3)(4), and Hf(NO3)(4), were used as single-source precursors to the component oxides. The compositions were mapped using X-ray photoelectron spectroscopy and Rutherford backscattering spectrometry. On a single wafer an array of 100 mum x 100 mum capacitors was used to map the effective dielectric constant (K-eff) of the films. For compositional spreads grown at 400 and 450 degreesC K-eff reached a maximum value in regions with the highest concentrations of TiO2. The formation of the orthorhombic alpha-PbO2 phase for a composition near Hf0.75Sn0.25O2 was also observed in the 450 degreesC compositional spread.