Fabrication Methodology
Sculpting tiny mechanical structures directly into semiconductor wafers enables the creation of high performance sensors. Through the application of silicon micromachining, engineers produce suspended beams and thin diaphragms that react to minuscule changes in force. This technology miniaturizes instruments that previously required bulky mechanical assemblies.
Manufacturing Sequence
Steps include the selective deposition of films followed by the strategic removal of substrate material. Because silicon micromachining uses standard photolithography, hundreds of independent devices can be manufactured simultaneously on one batch. This parallel production reduces individual unit costs while maintaining strict dimensional tolerances.
Device Morphology
Mechanical properties like resonant frequency depend on the final geometry after the sacrificial layers go away. Silicon micromachining allows for the integration of sensors and electronics on the same piece of silicon for faster signal response. Metrology labs use scanning electron microscopes to verify that the undercuts are clean and free of debris.
Stability Requirement
Internal stress within the deposited films must stay low to avoid curling or fracture of the tiny structures. If the silicon micromachining process results in high residual strain, the zero offset of the sensor will shift unpredictably over time. Proper control of the plasma chemistry keeps these stresses within the required operational window.
