The choice of materials for MEMS production depends on the specific application, as well as the desired performance, cost, and processing requirements. However, some common materials used in MEMS fabrication include:
Silicon: Silicon is the most commonly used material in MEMS production due to its excellent mechanical, electrical, and optical properties. It is also readily available and relatively inexpensive. Silicon can be etched using both wet and dry etching techniques, which allows for the creation of complex 3D structures.
Silicon dioxide: Silicon dioxide is used as a passivation layer in MEMS fabrication to protect the device from contamination and to maintain its electrical properties. It is also used as an etch mask for deep reactive ion etching (DRIE).
Metals: Metals are used in MEMS production for a variety of applications, including as electrodes, interconnects, and structural components. Common metals used in MEMS fabrication include aluminum, gold, and copper.
Polymers: Polymers are used in MEMS production for their flexibility, biocompatibility, and ease of processing. They can be used for a variety of applications, including as coatings, adhesives, and structural components.
Glass: Glass is used in MEMS production for its optical properties and biocompatibility. It is commonly used in the fabrication of microfluidic devices and lab-on-a-chip systems.
Other materials used in MEMS fabrication include ceramics, piezoelectric materials, and semiconductors such as gallium arsenide and indium phosphide.