Fig. 4: Etch rate characteristics of AlN and AlScN films, and sidewall profiles of AlScN films.

a Graph of ICP etch rate for pure AlN and AlScN films with varying Sc concentrations84. b Graph of KOH etch rate for AlScN films as a function of Sc concentration87. Scanning electron microscope (SEM) images of c the sidewall angle of an AlScN film etched by KOH, d the sidewall angle of an AlScN film etched by TMAH88, e residues remaining after TMAH etching, and f undercut observed after TMAH etching