Attainment of dual-band edge work function by using a single metal gate and single high-k dielectric via ion implantation for HP CMOS device

•Dual band-edge EWF are achieved by single metal/single high k via ion implantation.•VFB modulations of −750 mV/570 mV for N/P MOS device are achieved respectively.•Low Vt is obtained while shrinking EOT, no degradation of IG, μeff & reliability.•LG 25 nm HKMG CMOSFETs & 32 frequency dividers were fabricated successfully.

Attainment of dual band-edge effective work functions by using a single metal gate and single high k gate dielectric via P/BF2 implantation into a TiN metal gate for HP HKMG CMOS device applications are investigated under a gate-last process flow for the first time. The flat band voltage (VFB) modulations of about −750 mV/570 mV for N-/P-type MOS device with P/BF2 implanted TiN/HfO2/ILSiO2 gate stack are obtained respectively in the experiment range. Suitable low threshold voltages of CMOSFETs are gotten while simultaneously shrinking the EOT. The effects of P/BF2 ion implantation energy, dose and TiN gate thickness on the properties of implanted TiN/HfO2/ILSiO2 gate stack are studied, the possible mechanisms are discussed. This technique has been successfully integrated into the fabrications of aggressively scaled HP HKMG CMOSFETs and 32 CMOS frequency dividers under a gate-last process flow.

Graphical abstractC–V characteristics of TiN (3 nm)/HfO2 (2.4 nm)/ILSiO2 gate stack for N/PMOS CAP without and with different P/BF2 implant energies and doses, respectively, after 400 °C PMA, (a) with different P implant energies at fixed dose of 3 × 1014 cm−2. (b) With different P implant doses at fixed energy of 2.3 keV. (c) With different BF2 implant energies at fixed dose of 4.8 × 1014 cm−2. (d) With different BF2 implant doses at fixed energy of 4.4 keV.Figure optionsDownload full-size imageDownload as PowerPoint slide