Impact of Si DRIE on Vibratory MEMS Gyroscope Performance

Merz, P.; Pilz, W.; Senger, Frank; Reimer, K.; Grouchko, M.; Pandhumsoporn, Tam; Bösch, Wolfgang; Cofer, Anthony G.; Lassig, S.

doi:10.1109/sensor.2007.4300348

Cited by 27 publications

(10 citation statements)

References 2 publications

(1 reference statement)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Later on Lam Research, one of the big Californian plasma etch equipment suppliers, reported about successful low quadrature development activities on 150 mm wafers together with Fraunhofer Institute ISIT, Germany on their TCP DSiE reactor with a flat coil plasma source. Customer demo runs on 150 mm substrates also turned out much lower quadrature values on Bosch gyroscope devices, being the decision point to invest into a Lam trench etch equipment for Bosch production site.…”

Section: The Vision Becomes Realitymentioning

confidence: 99%

MEMS at Bosch – Si plasma etch success story, history, applications, and products

Laermer

Urban

2019

Plasma Processes & Polymers

View full text Add to dashboard Cite

MEMS (micro electro mechanical systems) are tiny mechanical structures in the micrometer range combined with an ASIC (application specific integrated circuit). MEMS at Bosch look back on more than 25 years of development and production and started based on KOH wet‐etching with restrictions in geometry due to the crystal‐oriented etch behavior of KOH. Based on several years of experience in plasma processing and the availability of new prototype plasma sources, the “Bosch Process,” a three‐dimensional plasma etch process for silicon was invented. This is the key enabler for today's huge variety of MEMS products in our every day life.

show abstract

Section: The Vision Becomes Realitymentioning

confidence: 99%

MEMS at Bosch – Si plasma etch success story, history, applications, and products

Laermer

Urban

2019

Plasma Processes & Polymers

View full text Add to dashboard Cite

show abstract

“…The mechanical unbalance which is coupling the primary and the secondary mode is due to a distortion of the rectangular shaped cross sections of the beam elements, in particular at the drive meanders. In the mathematical model derived below this effect will be accounted for by means of beam elements with rhomboid cross sections characterized by the so-called side wall angle n, see Merz et al (2007). All electrostatic actuators are assumed to be voltage controlled with a desired input voltage, see, e.g., Seeger and Boser (2003).…”

Section: Principle Of Operationmentioning

confidence: 99%

A dynamical envelope model for vibratory gyroscopes

Egretzberger

Kugi

2009

Microsyst Technol

View full text Add to dashboard Cite

In this contribution, a method will be presented to derive an envelope model for vibratory gyroscopes capturing the essential ''slow'' dynamics (envelope) of the system. The methodology will be exemplarily carried out for a capacitive gyroscope with electrostatic actuators and sensors. The resulting envelope model can be utilized for both transient and steady state simulations with the advantage of a significantly increased simulation speed. Especially for the sensor design and optimization, where usually very complex mathematical models are used, efficient steady state simulations are of certain interest. Another great advantage of this approach is that the steady state solutions in terms of the envelope model are constant. Thus, for the controller design, a linearization of the nonlinear envelope model around the steady state solution yields a linear time-invariant system allowing for the application of the powerful methods known from linear control theory.

show abstract

“…Indeed, on most of the MEMS gyroscope designs, one or several springs are place symmetrically on each corner of the resonator so that if all of the springs are identical, the resulting coupling stiffness is null [ 30 ]. However, if there is geometrical dispersion of the flexure springs, especially width variation as it is a critical dimension for the springs, the resulting coupling stiffness would not be equal to zero [ 37 ], which would generate a quadrature force. To our knowledge, few investigations have been carried out about the contributions of the geometrical dispersion of the springs on quadrature error.…”

Section: Introductionmentioning

confidence: 99%

The Effect of the Bending Beam Width Variations on the Discrepancy of the Resulting Quadrature Errors in MEMS Gyroscopes

et al. 2022

View full text Add to dashboard Cite

In this paper, we develop a new approach in order to understand the origin of the quadrature error in MEMS gyroscopes. As the width of the flexure springs is a critical parameter in the MEMS design, it is necessary to investigate the impact of the width variations on the stiffness coupling, which can generate a quadrature signal. To do so, we developed a method to determine the evolution of the stiffness matrix of the gyroscope springs with respect to the variation of the bending beams width of the springs through finite element analysis (FEA). Then, a statistical analysis permits the computation of the first two statistical moments of the quadrature error for a given beam width defect. It turns out that even small silicon etching defects can generate high quadrature level with up to a root mean square (RMS) value of 1220°/s for a bending beam width defect of 0.9%. Moreover, the quadrature error obtained through simulations has the same order of magnitude as the ones measured on the gyroscopes. This result constitutes a great help for designing MEMS gyroscopes, as the consideration of the bending beams width defects is needed in order to avoid high quadrature error.

show abstract

Impact of Si DRIE on Vibratory MEMS Gyroscope Performance

Cited by 27 publications

References 2 publications

MEMS at Bosch – Si plasma etch success story, history, applications, and products

MEMS at Bosch – Si plasma etch success story, history, applications, and products

A dynamical envelope model for vibratory gyroscopes

The Effect of the Bending Beam Width Variations on the Discrepancy of the Resulting Quadrature Errors in MEMS Gyroscopes

Contact Info

Product

Resources

About