SENSOR exhibition, 8-10 May 2001, booth # 2-216, Nürnberg, Germany

Nürnberg, May 8, 2001 --- IMEC has developed a technique to manufacture micro-electromechanical systems (MEMS) making use of U profiles. Such U profiles have a very high mechanical rigidity that enables the fabrication of very thin MEMS. With this technique, fast and sensitive microbolometers have been created with a thickness of only 0.1µm to 0.2µm.

Surface micromachining is a powerful and promising method for the fabrication of Si-based micro-electromechanical systems (MEMS), such as infrared bolometers. Infrared bolometers,  have previously been produced  at IMEC using long supporting beams with sub-micron dimensions, consisting of a material with low thermal conductance such as polycrystalline SiGe. To maximize sensitivity and speed, the sensor and its support beams should be as thin as possible. However, this makes the sensor element extremely fragile, both during processing and during use. Any stress gradients in the composing layers cause bending of the device, leading to failure. To date, this has limited the material choice and minimal thickness for a host of surface-micromachined sensors and actuators.

IMEC has found and patented a fundamental solution to the above problems: U-shaped profiles. These profiles feature a very high mechanical rigidity at reduced weight and can be easily produced using surface micromachining. Compared to a solid beam with the same dimensions, rigidity increases by up to three orders of magnitude.

This gain in mechanical strength has enabled fabrication of very thin bolometers (as thin as 0.1 µm), which are still capable of coping with the destructive forces during the etch process and effectively solve the problem of residual strain gradients in the material. Furthermore, the thermal loss through the two support beams is even lower than the radiative heat loss of the sensor. The benefits of this new approach are not limited to bolometers since increased rigidity  is relevant for a large number of surface-micromachined devices, such as actuators and sensors.

IMEC has licensed this technology to XenICs, (IMEC’s most recent spin-off company), for the commercialization of bolometers using U profiles.

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Notes to editors:

About IMEC

IMEC was founded in 1984 and today is Europe's leading independent research center for the development and licensing of microelectronics, and information and communication technologies (ICT). IMEC is headquartered in Leuven, Belgium, and has a staff of more than 1000 people including more than 200 industrial residents. Its more than $100 million revenue is derived from agreements and contracts with Flemish government, the EC, MEDEA, the European Space Agency, equipment and material suppliers and semiconductor companies worldwide. IMEC's activities concentrate on design of integrated information and communication systems; silicon process technology; silicon technology and device integration; microsystems, components and packaging; advanced training in microelectronics. IMEC has a sub-0.25µm 200mm pilot line and is ISO9001 certified. News from IMEC is located at www.imec.be.

For more information:

Katrien Marent

Communication Manager

Public Relations and Marketing Communications

IMEC, Kapeldreef 75

B- 3001 Leuven, Belgium

Tel +32 16 28 18 80 Fax +32 16 28 16 37

Email: Katrien.Marent@imec.be