Crystallographic edge removal of silicon dioxide micro-parts in bulk micromachining

The purpose of this research was to find a cost-effective and repeatable method for releasing high-quality micro-parts from a silicon substrate by bulk micromachining technology. Crystallographic shape removal technology on the finally released silicon oxide parts was put into scrutiny. Several methods were approached as possible solutions. These methods include ethylenediamine – pyrocatechol – water etchant, the addition of a boron dopant to the silicon dioxide layer, pre-thinning of wafers and the use of polyimide coatings to thin the silicon substrate subsequent to part release. The combined method of boron doping and polyimide coating produced the best results.