High-K metal gate stacks with ultra-thin interfacial layers formed by low temperature microwave-based plasma oxidation

•TiN/HfO2 high-K metal gate stacks with ultra-thin interfacial SiO2 layers•Microwave-based plasma oxidation at temperatures below 200 °C•Plasma oxides with excellent electrical properties comparable to thermal oxides•Layers grown in H2/He/O2 plasma are the best in interface trap density.

Ultra-thin interfacial silicon oxide layers are grown by microwave-based plasma oxidation at temperatures below 200 °C. The influence of plasma gas composition and plasma pulsing on layer properties is tested. The oxides are compared to standard thermally grown oxide and wet chemical oxide. Layer properties are evaluated by x-ray photo electron spectroscopy and are electrically characterized by means of TiN/HfO2/SiO2 high-k metal gate stacks.

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