4H-SiC MOSFETs Using Thermal Oxidized Ta_2Si Films as High-k Gate Dielectric

摘要

Oxidized Ta_2Si layers have been used as high-k dielectric layer for 4H-SiC MOSFETs. The gate insulator was grown by dry oxidation of 40nm deposited Ta_2Si during 1h at 1050℃. The dielectric constant obtained from 4H-SiC MIS capacitors is ～20 with an insulator thickness of 150nm. These devices exhibit adequate subthreshold, saturation and drive characteristics. For the MOSFETs fabricated on a p-implanted and annealed region, a peak mobility up to 45cm~2/Vs has been extracted. The specific on-resistance of this device is 29mΩ· cm~2 at room temperature with V_(DS)=0.2V and V_(GS)=14V.