Low inversion equivalent oxide thickness and enhanced mobility in MOSFETs with chlorine plasma interface engineering

• Cl2 plasma treated devices show better electrical characteristics than CF4 ones.
• 0.76 nm Tinv with decreased leakage current is achieved by Cl2 plasma treatment.
• Cl2 plasma treated device shows ∼150 cm2/V s electron mobility.
• The possible mechanisms for Cl2 and CF4 plasma treatments are proposed.
• Cl2 plasma treated IL is promising for advanced MOSFETs.

High-k gated metal–oxide–semiconductor field-effect-transistors (MOSFETs) with Cl2 and CF4 plasma treatments are studied in this work. A higher-k HfON with more tetragonal phase is formed by the halogen plasma treatment on interfacial layer (IL). A low inversion equivalent oxide thickness in MOSFET is obtained with the Cl2 plasma treated IL. In addition, high mobility and transconductance, and low subthreshold swing are obtained by the Cl2 plasma treatment, which therefore is a promising interface engineering for advanced MOSFETs.