Characterisation of aluminium passivation for TMAH based anisotropic etching for MEMS applications

A cross-bridge linewidth test structure has been used to analyse, both electrically and physically, the effect of a new anisotropic silicon etch composition that has been designed to have an increased selectivity with aluminium. To characterise the effect of the etch on aluminium tracks, electrical measurements have been made to obtain sheet resistance and linewidth. These results are presented in combination with SEM micrographs to evaluate the surface quality of the exposed aluminium.