A wide bandgap, an enhanced piezoelectric coefficient, and low dielectric permittivity are some of the outstanding properties that have made ${\mathrm{Sc}}_{\mathrm{x}}{\mathrm{Al}}_{1-\mathrm{x}}\mathrm{N}$ a promising material in numerous MEMS and optoelectronics applications. One of the substantial challenges of fabricating ${\mathrm{Sc}}_{\mathrm{x}}{\mathrm{Al}}_{1-\mathrm{x}}\mathrm{N}$ devices is its difficulty in etching, specifically with higher scandium concentration. In this work, we have developed an experimental approach with high temperature annealing followed by a wet etching process using tetramethyl ammonium hydroxide (TMAH), which maintains etching uniformity across various Sc compositions. The experimental results of etching approximately 730 nm of ${\mathrm{Sc}}_{\mathrm{x}}{\mathrm{Al}}_{1-\mathrm{x}}\mathrm{N}$ (x = 0.125, 0.20, 0.40) thin films show that the etch rate decreases with increasing scandium content. Nevertheless, sidewall verticality of 85°~90° (±0.2°) was maintained for all Sc compositions. Based on these experimental outcomes, it is anticipated that this etching procedure will be advantageous in the fabrication of acoustic, photonic, and piezoelectric devices.