Open Access Paper
1 July 2005 SIGEM, low-temperature deposition of poly-SiGe MEMs structures on standard CMOS circuits (Invited Paper)
Juan Ramos-Martos, Joaquin Ceballos-Caceres, Antonio Ragel-Morales, Jose Miguel Mora-Gutierrez, Alberto Arias-Drake, Miguel Angel Lagos-Florido, Jose Maria Munoz-Hinojosa, Anshu Mehta, Agnes Verbist, Bert du Bois, Kersten Kehr, Christina Leinenbach, Steven Van Aerde, Jorg Spengler, Ann Witvrouw
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Proceedings Volume 5836, Smart Sensors, Actuators, and MEMS II; (2005) https://doi.org/10.1117/12.608499
Event: Microtechnologies for the New Millennium 2005, 2005, Sevilla, Spain
Abstract
Fabrication of surface-micromachined structures by a post-processing module above standard IC circuits is an efficient way to produce monolithic microsystems, allowing nearly independent optimization of the circuitry and the MEMS process. However, until now the high-temperature steps needed for deposition of poly-Si have limited its application. SiGeM explores the possibilities offered by the low-temperature (450°C) deposition and structuring of poly-SiGe layers, which is compatible with the temperature budget of fully-processed standard IC wafers. In the SiGeM project several low-temperature deposition methods (CVD, PECVD, LPCVD) were developed, and were evaluated with respect to growth rate and material quality. The interconnection technology to the underlying CMOS circuitry was also developed. The capabilities of this new integration technology will be demonstrated in a monolithic high-performance rate-of-turn sensor, currently considered the most demanding MEMs application in terms of material properties of the structural layer (thickness > 10mm, stress gradient < 0.3MPa/mm) and signal processing circuitry (capacitance resolution in the aF range, SNR > 110 dB). System partitioning will combine analog and DSP circuit techniques to maximize resolution and stability. Parasitic electrical coupling within different parts of the system has been analyzed, and countermeasures to reduce it have been incorporated in the design. The feasibility of the approach has already been proved by preliminary characterization of working prototypes containing released microstructures deposited on top of preamplifier circuits built on a 0.35mm, 5-metal, 2-poly, standard CMOS process from Philips Semiconductors. Resonance frequencies are in good agreement with predictions, and quality factors above 8000 have been obtained at pressures of 0.8 mTorr. Measured SNR confirms the capability to achieve a resolution of 0.015°/s over a bandwidth of 50 Hz.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Juan Ramos-Martos, Joaquin Ceballos-Caceres, Antonio Ragel-Morales, Jose Miguel Mora-Gutierrez, Alberto Arias-Drake, Miguel Angel Lagos-Florido, Jose Maria Munoz-Hinojosa, Anshu Mehta, Agnes Verbist, Bert du Bois, Kersten Kehr, Christina Leinenbach, Steven Van Aerde, Jorg Spengler, and Ann Witvrouw "SIGEM, low-temperature deposition of poly-SiGe MEMs structures on standard CMOS circuits (Invited Paper)", Proc. SPIE 5836, Smart Sensors, Actuators, and MEMS II, (1 July 2005); https://doi.org/10.1117/12.608499
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Cited by 2 scholarly publications.
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KEYWORDS
Amplifiers

Signal to noise ratio

Modulators

Sensors

Signal detection

Microelectromechanical systems

Digital signal processing

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