TY - JOUR AU - Pal, Prem AU - Sato, Kazuo PY - 2015 DA - 2015/05/27 TI - A comprehensive review on convex and concave corners in silicon bulk micromachining based on anisotropic wet chemical etching JO - Micro and Nano Systems Letters SP - 6 VL - 3 IS - 1 AB - Wet anisotropic etching based silicon micromachining is an important technique to fabricate freestanding (e.g. cantilever) and fixed (e.g. cavity) structures on different orientation silicon wafers for various applications in microelectromechanical systems (MEMS). {111} planes are the slowest etch rate plane in all kinds of anisotropic etchants and therefore, a prolonged etching always leads to the appearance of {111} facets at the sidewalls of the fabricated structures. In wet anisotropic etching, undercutting occurs at the extruded corners and the curved edges of the mask patterns on the wafer surface. The rate of undercutting depends upon the type of etchant and the shape of mask edges and corners. Furthermore, the undercutting takes place at the straight edges if they do not contain {111} planes. {100} and {110} silicon wafers are most widely used in MEMS as well as microelectronics fabrication. SN - 2213-9621 UR - https://doi.org/10.1186/s40486-015-0012-4 DO - 10.1186/s40486-015-0012-4 ID - Pal2015 ER -