Abstract
The shear strength of microridges fabricated using both anisotropic wet etching (KOH, TMAH and EDP) and dry-etching methods (chlorine RIE) is presented in this paper. Shear strengths obtained using a KOH wet etching is concentration dependent, that is the microridges made with a 45% KOH solution has a strength 65% larger than those by 30% KOH. EDP and TMAH wet etching produce structures whose average strengths are similar to the 30% KOH solution. On the other hand, dry etching chlorine RIE produces structures with strength values 95% higher than the wet etching approaches containing similar crystal orientations. Strength variations are attributed to local stress concentrations. RIE is also used to manufacture structures with different crystal orientations. Test results indicate that microridges with a {110} sidewall has the highest strength because for this case the loading direction (perpendicular to sidewall) has one of the smallest component along the {111} plane (sliding plane of silicon). Microridges made with a sidewall of {100} plane produce the lowest strength value among the three crystal orientations studied.