Etch rates for micromachining processing

Abstract

The etch rates for 317 combinations of 16 materials (single-crystal silicon, doped, and undoped polysilicon, several types of silicon dioxide, stoichiometric and silicon-rich silicon nitride, aluminum, tungsten, titanium, Ti/W alloy, and two brands of positive photoresist) used in the fabrication of microelectromechanical systems and integrated circuits in 28 wet, plasma, and plasmaless-gas-phase etches (several HF solutions, H3PO4, HNO3 + H2O + NH4F, KOH, Type A aluminum etchant, H2O + H2O2 + HF, H2O2, piranha, acetone, HF vapor, XeF2, and various combinations of SF6, CF4, CHF3, Cl2, O2, N2, and He in plasmas) were measured and are tabulated. Etch preparation, use, and chemical reactions (from the technical literature) are given. Sample preparation and MEMS applications are described for the materials. [193].