Materials for MEMS
Substrates and Wafers
Active Substrate Materials
Silicon as a Substrate Material
- The Ideal Substrate for MEMS
- Single-Crystal Silicon and Wafers
- Crystal Structure
- The Miller Indices
- Mechanical Properties of Silicon
- Silicon Dioxide
- Silicon Carbide
- Silicon Nitride
- Polycrystalline Silicon
- Polymers as Industrial Materials
- Polymers for MEMS and Microsystems
- Conductive Polymers
- The Langmuir-Blodgett (LB) Film
2. Substrates and Wafers
The frequently used term substrate in microelectronics means a flat macroscopic object on which microfabrication processes take place. In microsystems, a substrate serves an additional purpose : it acts as single transducer besides supporting other transducers that convert mechanical actions to electrical outputs or vice versa.
In semiconductors, the substrate is a crystal cut in slices from a larger piece called a wafer. Wafer can be of silicon or other single crystalline material such as quartz or gallium arsenide.
Substrates in microsystems, however, are somewhat different. There are two types of substrate materials used in microsystems : (1) active substrate materials and (2) passive substrate materials.