The polarity dependence of capacitances for HfO2 affected by post-CF4 plasma treatment

The polarity dependence of capacitances for HfO₂ was first investigated in this work. A novel approach to improve HfO₂ gate dielectrics by post-CF₄ plasma treatment was proposed also. After HfO₂ thin film deposition, post-CF₄ plasma treatment was demonstrated to introduce the fluorine to incorporate in HfO₂ thin film. Gate leakage current was improved at the direct tunneling region, and decreased 1∼2 order at the F-N tunneling region with increasing CF₄ plasma treatment time. The physical trapping model was proposed to explain the C-V hysteresis phenomenon under different measuring loops.