The quality of sound recording in consumer devices could soon be improved with a high quality microphone based on very low cost CMOS device technology.

Acoustic silicon specialist Akustica is working with German mixed-signal foundry X-Fab Semiconductor to produce the first single chip CMOS microphone design based on micro-electromechanical systems (MEMS) technology which can offer noise cancellation.

"This is the first semiconductor technology application to produce MEMS microphone chips using a CMOS process flow," said Manfred Riemer, chief operating officer of X-FAB, “resulting in cost-effective new microphone solutions for the marketplace."

The device is the AKU2000 digital output microphone chip which is aimed at use in PC laptops, digital video and still cameras. One application is in microphone arrays where multiple microphones will be used together to perform noise cancellation and/or beamforming.

“The market for MEMS microphones will explode from around $55m in 2005 to $680m in 2010, mainly for mobile phone applications, laptops, and digital media electronics," said Richard Dixon of Munich-based analyst company Wicht Technologie Consulting.

The significance of CMOS MEMS structures is that they are composed of the metal-dielectric structures within a standard CMOS wafer and so new types of acoustic device can be fabricated in volume using a standard CMOS process.

Dixon believes the MEMS CMOS devices have the potential to meet the low price points of established electric condenser microphones.

It is likely that MEMS microphones are particularly suited to space-constrained and RF-rich environments such as mobile phones. “They are also ideal for directionality and noise cancellation applications in laptops,” said Dixon.

www.akustica.com