The Idonus HF Vapor Phase Etching System is used to etch SiO2. It provides a variety of new processing options for MEMS fabrication. The system consists of a reaction chamber, a wafer holder, and a controller. The wafer holder accommodates small substrate pieces as well as wafers up to 6” in diameter. A heating element is integrated into the wafer holder. The etching rate can be controlled by adjusting the wafer temperature from 35°C to 60°C. The etching process can also be done at room temperature.