3D Vibration Analysis of microsystems (MEMS Analyser)

MSA-500

Micro-System Analyser

Measuring 3D-Dynamics and Topography of MEMS and Microstructures

Contact :

Etienne Herth
Bâtiment TEMIS Sciences, bureau N3
03 63 08 24 70 (Office)
03 63 08 24 18 (Lab 02-Temis)
Etienne.herth@femto-st.fr

Localization :

Building TEMIS
Lab 02

Overview :

This system measurement on the microstructures MEMS, MOEMS and NEMS finds the resonance frequencies modes with many Scan Points in a short time. Theses resonances frequencies can presented like an Amplitude, phase or Impedance. Moreover, the mechanical behaviors of these resonances frequencies modes can show by the deflection Shapes 3D animation. Initially, people were more interested in working on vertical resonators because it was technologically easier to fabricate. The majority of recent demonstrator devices are using lateral technologies mainly because of the design flexibility: squares, disks, beams etc. These resonators can be classed by the vibrating direction: Out of plane (vertical resonators) and In plane (lateral resonators). So, in our equipment, we have two dynamical measurements in one: In-plane and Out- of-plane. We know that the resonant frequency increases when the beam stiffness increases, so smaller resonator sizes induce a resonant frequency increase. The dynamical measurement In-Plane use the Laser Doppler Vibrometry @ 20 MHz. The Out-of-plane use the Stroboscopic Video Microscopy @ 2 MHz. In this case, video camera captures images that are used to determine the movement of the microstructures such as the Comb-drives. It is well known that this displacement is in the nanometer range (nearly 10–20 nm for the beam, 1–5 nm for the disk). In our system, the resolution is picometer range and nanometer range respectively for In plane and out of plane measurement.

Technical characteristics :

Out-of-plane Vibration (Laser Doppler Vibrometry)

• Displacement (linked to phase of Doppler signal)
  

Analog Decoder: DD300
Frequency: 0-20 MHz
Displacement: ±75nm
Resolution: 250 pm (magnification independent)

• Velocity (linked to frequency of Doppler signal)
  

Digital Decoder: Two decoders

VD 06:
Frequency: 0-350 kHz
Max. velocity : ± 0.5 m/s
Resolution: 0.01-0.05 µm/s/√Hz

VD 09:
Frequency: 0-2.5 MHz
Max. velocity : ± 10 m/s
Resolution: 0.02-0.2 µm/s/√Hz

In-Plane Vibration (Stroboscopic Video Microscopy)

Video Stroboscopic: LED + Digital Camera

• Visualize fast in plane movements by video stroboscopy
• Snapshot illumination by very short stroboscope flashes
• Series of snapshot pictures at different phases of the vibration
  
  

Topography 3 D (White Light Interferometry)

Video Stroboscopic: LED + Digital Camera

• Z Resolution : ≈ nm range
• Lat. resolution: ≈ 500 nm (magnification dependent)
• Objective : Mirau x10
• Piezo scans z-direction : ≈ 250µm