In this work, we demonstrate a deep mesa etch design for efficient edge field termination in β-Ga2O3 Schottky barrier diodes (SBDs). The proposed design enabled parallel plate fields higher than 4.1 MV/cm with negligible change to the device ON characteristics. The effect of BCl3/Cl2-based dry etch on (100) and (010) etched vertical sidewalls is also analyzed. A remarkable anisotropy in depletion was observed for etch along (100) and (010) sidewalls. This work provides insight into the impact of etching on n-type Ga2O3 and shows a promising method to realize efficient field termination for high breakdown field strength SBDs.