MEMS for Mobile Applications Surge
Mobile phones and tablets continue to be the main drivers of the MEMS market growth, with Apple and Samsung the dominant buyers of MEMS for consumer and mobile devices. To increase functionality and reduce device footprint, MEMS makers are introducing “motion combo sensors” which combine gyroscopes, accelerometers, and even magnetometers into one package. iSuppli estimates that the market for these combo sensors could increase by over 230% in 2013.
Motion Combo Sensor
Typical Microphone Cavity Etch
In addition to motion sensors, MEMS-based microphones are taking the slots previously occupied by electret condenser microphones (ECMs). MEMS microphones are more compact than ECMs because they capture sound and convert it to a digital signal on the same chip. The system architecture can be made completely digital, removing noise-prone analogue signals and simplifying the overall design. In many cases, portable electronic products incorporate multiple microphones for noise suppression, further increasing demand. Until recently, digital MEMS microphones were relatively expensive, but with more manufacturers entering this market, competition has forced prices down. TechNavio predicts a 22% compound annual growth rate (CAGR) for MEMS microphones from 2011 to 2015, while iSuppli states that MEMS microphones have already replaced half the conventional ECMs in smartphones and forecasts that in 2013, revenue generated from digital MEMS microphones will hit $315 million and overtake the analog MEMS equivalent.
SPTS has served the MEMS market since their development of the first commercially-available deep reactive ion etch (DRIE) system in collaboration Robert Bosch GmbH, in the early 1990s, and DRIE is a key enabling process for both motion sensors and MEMS microphones.
SPTS offers many process technologies to the MEMS market, including:
- DRIE for deep, anisotropic silicon etching
- Dry HF vapour etch for isotropic etching of sacrificial oxide layers to release silicon MEMS
- PVD of aluminium nitride
- PECVD of dielectrics
- LPCVD of low stress SiN, thick polysilicon and SiGe