CORDIS - Forschungsergebnisse der EU
CORDIS

Silicon Microphone

Final Report Summary - SIMIC (Silicon Microphone)

MEMS (Micro-Electrical-Mechanical System) based microphones, so called “silicon microphones” - are relevant in many applications as their manufacturability is better compared to electret condenser mics (ECM). Often MEMS mics hold embedded ADCs (Analog-to-Digital Converter) on the same CMOS chip. Those “digital output mics” perfectly fit into innovative digital products e.g. smart phones. Extremely small form factors and better performance in dynamic range and high sound pressure levels (voice recognition&command, music recording) are highly requested.
The project aims to develop revolutionary components for Silicon based microphones (SiMic) that can satisfy the new challenging requirements of multiple marketplaces. Smart phones need up to three microphones each and the produced volumes tend into several billion pieces per year – one of the strongest increasing market demands worldwide. It is of vital interest for European academia and semiconductor manufacturers to be at the top with developments. Academia needs possibilities to work on solutions nobody has ever thought of and industry has to follow the needs of the global customers. The requirements of microphones for mobile applications have significantly increased from acceptable telephone quality with signal to noise ratio of 58dB(A) up to a State-of-the-Art SNR of >64dB(A). The desire to record music with ultimate dynamic range of more than 110dB still pushes for lower ground noise and higher linearity.
UC3M is well known for its highly innovative concepts and forefront research. Quality of those concepts strongly depend on features of the technologies needed for system integration, competitiveness of academia is connected to the access to latest manufacturing technologies. SiMic collaboration approach guarantees, that UC3M system and circuitry concepts will be leading edge within the EU. IFAT is the second largest supplier of SiMiCs using ASIC designs, similar to those used with ECM..
The funding will be used for target oriented innovation with room for creative concepts thus enabling new products for a growing market and investment in more resources at the research institute.
The project does not have a public website.
Summary description of project objectives and work performed
Performance of silicon microphone system is mainly influenced by 3 parts: the signal sensor MEMS - the interface, circuit (transforming the signal into processable data) - and a converter (ΣΔ ADC) delivering the digital output signal. SiMic project will address all those 3 parts. The objective of the SiMic project is to address and improve all these three core parts.
Objective 1: Core part MEMS (WP2)
Results of Objective 1:
- Simulation models for different types of MEMS are available
- Models are ready for design of read-out circuits
Objective 2: Core part Interface (WP1 and WP2)
Results of Objective 2:
- Test chip with a second order noise shaping sigma delta architecture proposed.
- Study of the actual IFAT Capacitive-to-Digital Converter (CDC) done by UC3M
- After the study UC3M designed and fabricated a new CDC incl. MEMS plus readout circuit.
Objective 3: Core part AD converter (WP3)
Results of Objective 3:
- Ultrasonic: Concept to extend the usable bandwith of the ADC finished
- Audio: Selection of architecture done

Expected final impact:
For IFAT the work so far is highly interesting in both technical/scientific as well as cooperation wise with the UC3M in the fight for the best talents on the market.
+ Development of new/old intersectoral cooperation:
The cooperation is very fruitful as it is based on already existing first experiences. There has not been any delay as the key scientists in charge already knew each other and could start on a reliable network. The researchers exchanged in the secondments are all highly motivated. The cooperation is going beyond the current project work. This is also shown by the visits Dr. Dietmar Straeussnigg had in Madrid where he gave lectures to students at the University. This was fully supported by Infineon.
+ Expectations to create a long-lasting strategic cooperation:
The results of the project are very promising for futher cooperations. Senior experts have been exchanged and additional plans for projects are already in the pipeline. Furthermore IFAT is giving secondees a chance to do project work in Villach (employment contract) after the project end.
The research carried out by UC3M enables Infineon to make use of concepts that are created outside the harsh business environment with all the restrictions given by budget and time pressure. These concepts are developed in a kind of “free” research area and ready for studies on possible applications. Therefore already at this stage of the project concepts have been evaluated and feasibility studies have been carried out.
+ Impact on the future career prospects of the secondees:
All secondees are directly involved in the structures and organization of IFAT in Villach, being directly exposed to real industrial procedures, methodologies and processes. Furthermore they get direct insight into real business interactions.
+ Benefit to the mobility to the REA:
There is a frequent exchange of students (internships) between Austria and Spain building up a close cooperation via networks established during these exchange periods