The plasma sheath bending effect is widely observed in the wafer edge where the transition area to the edge ring is located. It is due to the electrical discontinuity and results in the difference in Ion Electron Angle Distribution (IEAD) between wafer extreme edge and inner wafer. As the aspect ratio increases during semiconductor scaling, the profile of etching is getting progressively sensitive to the sheath bending effect, resulting in a tilting profile or abnormal CD at the wafer's extreme edge. In our work, we presented a novel approach to improve the process capability to control the uniformity and profile during a two-step Fin etching process, where Fin hard mask (HM) etching and Fin etching are implemented: 1) Fin HM etching is applied in a capacitively-coupled plasmas (CCP) etcher by fine-tuning the focus ring temperature and the by-zone temperature module for local non-uniformity improvement, with a uniformity of Fin Critical Dimension (CD) improved by 60%; 2) Fin etching is applied in an inductively-coupled plasma (ICP) etcher by fine-tuning the movable edge ring to improve the sheath bending effect, with a profile and uniformity meeting targets. The improvement of the dry etching process at the extreme wafer edge will be discussed in detail.