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Direct tunneling through the gate SiO2(εr≈4)has become a serious concern for metal-oxide semiconductor field effect transistor scaling. The semiconductor industry is focusing on dielectrics with high relative dielectric constants (εr≥10)to replace SiO2gate oxides. Among the potential high-kmaterials, oxides and silicates of hafnium (Hf) have shown the most promise. The possibility of process cross-contamination by integrating these materials into silicon processes is a major concern for integrated circuit manufacturers. Cross-contamination of Hf in a plasma etch tool has been investigated. These studies confirm that significant cross-contamination occurs when HfO2is etched in a chloro-fluoro-carbon plasma etch system. None of the standard cleaning processes commonly used in the semiconductor industry (such as SC1 and SC2) completely remove the contamination; however, dilute hydrofluoric acid, hydrofluoric acid-hydrogen peroxide water mixture, and SC1 cleans removed contamination below the concentration thresholds for oxide degradation and close to the total reflection X-ray fluorescence detection limit.

A H2pre-bake at temperatures over 1050°C is typically used prior to Si epitaxial growth. In this study surface microroughness probed with tapping mode Atomic Force Microscopy (AFM) is correlated with multiple internal reflection infrared spectroscopy measurements for the different steps involved before epitaxy. A novel sample preparation technique was used for the multiple internal reflection set-up. A strong correlation was found between the presence of surface terraces and the IR double monohydride peaks for H2annealed Si surfaces. We therefore put forward that the terraces are due to the H2pre-bake step. These terraces remain after epitaxial deposition.