MEMS FABRICATION


MEMS Devices (Micro-Electro-Mechanical Systems) have found over the last decade a major interest for a variety of applications. MEMS devices incorporate micron-sized mechanical elements, such as sensors and actuators. MEMS technology utilizes to a large extent fabrication processes originally developed for semiconductor chips, such as micro-lithography, selective etching and patterning, deposition of conductive and insulating layers, impurity implantations and annealing, thermal diffusion and oxidation processes.


The physical dimensions of MEMS devices are considerably larger than those for advanced microchips, such as micro-processors and memory chips. Therefore, the MEMS fabrication processes require less stringent fabrication conditions than those for the production of microchips. Many MEMS devices use silicon wafers for the starting material. Silicon substrates offer the additional advantage that signal-processing circuitry can be incorporated into the MEMS chips. Several hundreds of MEMS devices can be produced on a single silicon wafer in a batch process.


Samples of commercial MEMS applications are:

  • Accelerometers for automotive air bag deployment
  • Pressure sensors for automotive and medical applications
  • Bio-sensors and chemo-sensors for medical and health related applications
  • Optical sensors and switches for communication systems
  • Gyroscopes for automotive and military applications
  • Ejectors for printers
  • Sensor tips for surface scanning microscopes

Tystar Corporation actively installed TYTAN furnace systems for several years at major research laboratories and universities involved in MEMS research and development, such as UC Berkeley, Georgia Tech, UCLA Nanolab, JPL, NIST, Oakridge National Lab, Princeton University, Harvard University, USC, KAUST in Saudi Arabia and others. In Taiwan, ROC, TYTAN furnaces are installed for MEMS research at ITRI, APMI, Walsin Liwah and others. In Singapore at NTU, NUS and others. Tystar maintains close relationships with those institutions and receives valuable feedback on process technology and performance, enhancing our ability to provide the MEMS users with the most advanced MEMS technology.


TYTAN Furnace systems can be used for all conventional atmospheric and low-pressure CVD processes employed in the semiconductor industry.


Tystar has developed and transferred to industry several unique processes for MEMS fabrication, including the deposition of low stress Si3N4 and thick poly-silicon films, deposition of low stress SiGe films, deposition of SiC films, thermal growth of thick SiO2 films and others.