Simulation of three-dimensional etch profile of silicon during orientation dependent anisotropic etching

A simulation program of a three-dimensional anisotropic etching profile is developed to design the fabrication processes of microstructures made of single crystal silicon. We can now predict a change in the shape of a silicon wafer having an arbitrary crystallographic orientation and an initial three dimensional shape including concave and convex edges. Contrary to the conventional method, which assumes that etch profiles are composed of limited crystallographic planes, the developed system makes it possible to use a number of different crystallographic planes. Using this system, we have developed two new processes for fabricating a three-dimensional microstructure. We called them a multi-step anisotropic etching process and a separated anisotropic etching process. This simulation system is a powerful tool for designing the new processes in fabricating three-dimensional microstructures.