Fabrication process combines surface & bulk micromachining

For the accurate high-volume production of 3D MEMS devices, including accelerometers, gyroscopes, microphones and pressure sensors, semiconductor manufacturers have previously relied on two manufacturing processes. Surface micromachining was often chosen for cost-effectiveness, while bulk micromachining was chosen for higher sensitivity and precision. Opening up the possibility to drive surface-micromachined MEMS into new markets and applications, the THELMA60 combines the advantages of both approaches. 

"Several companies have tried and failed to bring the precision and sensitivity of bulk micromachining to meet the higher-volume efficiencies of the growing IoT, consumer, and mobile markets," commented Jean-Christophe Eloy, President and CEO, Yole Développement. "ST has executed an innovative and effective end-run on the problem with its 60µm epitaxial layer surface-micromachining process."

Benedetto Vigna, Executive Vice President and General Manager, Analog, MEMS and Sensors Group, STMicroelectronics, said: "The introduction of ST's THELMA60 surface-micromachining process starts a new era for inertial sensors. As already proven by a number of design wins that are now entering production, THELMA60 is the ideal solution to increase cost efficiency for challenging applications that demand high sensitivity like implantable medical devices and high-end sensors for aerospace systems and seismic exploration - once the exclusive domain of bulk micromachining. After we have revolutionised the market for consumer inertial sensors, we are now set to change the game for high-end sensor applications. This is just the start."