Improvement of Line Roughness of Fin by Conventional Thermal Oxidation and Atomic Level Low-Temperature Ozone Treatments

In this paper, conventional thermal oxidation (CTO) and atomic level low-temperature ozone (LTO) treatment were utilized to successfully thin the width of fin and reduce the surface roughness. Meanwhile, the line edge roughness (LER) and line width roughness (LWR) of fin were compared under the two schemes. The result show that after three sacrificial oxidizations and DHF rinsing, the LER and LWR of fins were reduced by 40.1% (from 4.64 nm to 2.78 nm) and 55.5% (from 2.38 nm to 1.06 nm), respectively. In addition, after 12 cycles of LTO and HF rinsing, the LER and LWR of fin decreased by 67.4% (from 4.30 nm to 1.40 nm) and 61.3% (from 2.66 nm to 1.03 nm), respectively. And, the cross-correlation coefficients (ρ) were 0.92 and 0.72, respectively. The result provide a guidance for channel surface optimization and low-temperature integration of FinFET devices at advanced technology nodes.