High speed silicon wet anisotropic etching for applications in bulk micromachining: a review

Abstract Wet anisotropic etching is extensively employed in silicon bulk micromachining to fabricate microstructures for various applications the field of microelectromechanical systems (MEMS). In addition, it most widely used surface texturing minimize reflectance light improve efficiency crystalline solar cells. wet micromachining, etch rate a major factor that affects throughput. Slower increases fabrication time and therefore great concern MEMS industry where perform especially deep cavities freestanding by removal underneath material through undercutting process. Several methods have been proposed increase etchants either physical means (e.g. agitation, microwave irradiation) or chemically incorporation additives. The ultrasonic agitation during irradiation on rate. However, method may rupture fragile structures causes damage structures. Another temperature towards boiling point etchant. characteristics pure potassium hydroxide solution (KOH) studied near KOH, while surfactant added tetramethylammonium (TMAH) investigated at higher Both these studies shown potential way increasing elevating its point, which function concentration solution. effect kinds additives TMAH KOH. this paper, discussed. Recently hydroxylamine (NH 2 OH) KOH detail. NH OH TMAH/KOH varied optimize etchant composition obtain improved are important parameters article, different explored discussed so researchers/scientists/engineers can get details single reference.