Fabrication Infrastructure
Manufacturing of micro-electromechanical systems requires specialized semiconductor cleanrooms with process tools designed for bulk silicon etching, sacrificial layer release, and wafer-level bonding. A dedicated MEMS wafer foundry provides the physical infrastructure and process recipes to turn silicon wafers into microscopic sensors and actuators. This manufacturing environment is controlled for temperature, humidity, and airborne particulates to prevent defects in the micro-mechanical structures.
The cleanrooms must maintain a Class 10 or Class 100 environment to protect the moving, suspended silicon structures from microscopic dust particles.
Process Capability
Foundries offer specialized processes such as deep reactive-ion etching to form high-aspect-ratio trenches and structures. These processes allow the creation of suspended proof masses and micro-combs that form the core sensing elements of accelerometers and gyroscopes.
Tolerance Control
Deposition thickness and etching depths must be controlled to sub-nanometer tolerances to ensure consistent spring constants and capacitive gaps across the wafer. Variations in these physical dimensions will directly alter the sensitivity and natural frequency of the sensors, requiring individual calibration of the finished devices.
Foundry Sourcing
Selecting a foundry partner requires auditing their process stability, defect density, and baseline electrical characteristics. This qualification process ensures that the wafer yield remains high and that the manufactured sensors meet the strict specifications of industrial and automotive customers.
