Applications

MEMS

Accurate measurements of MEMS geometries and motions are crucial to achieving the desired performance of the devices. The wide variety of MEMS devices in development and production requires very flexible metrology for single-platform characterization. In addition to having greatly varying geometries, devices must also be characterized statically and/or under actuation.

  • Membrane thickness and uniformity mapping combined with visual inspection
  • Manufacturing of membranes by using surface micromachining requires control of membrane thickness and its uniformity. Membranes are released by using underneath sacrificial layers or by KOH etching. Following the membrane processing, visual defects must be detected to avoid MEMS reliability and integrity.

    Related products - MEMSCAN

  • Through silicon cap membrane shape, thickness and inspection
  • Wafer level packaging of MEMS devices can be done by bonding the active MEMS die with a top silicon cap wafer. Following the bonding process, membrane non planarity, visual defects and particles must be detected.

    Related products - MEMSCAN

  • Deep high aspect/ratio trench and via depth and CD’s
  • Bulk micromachining has been essential in enabling high performance MEMS sensors. With the use of deep reactive ion etching process, high aspect ratio structures can be achieved with vertical side walls (anisotropic etching). Standards techniques such as optical or confocal profilers can’t measure the depth of such structures. To save time and money, new metrology solutions are required to avoid destructive methods such as cross-section SEM.

    Related products - T-MAP DUAL 3D

  • Overlay registration and Front to back alignment
  • In plane overlay after bonding and front to back registration is used for MEMS manufacturing. NIR microscopy and DUAL microscopy (front and back) can be used for process control with less than 0.5 µm accuracy. FOGALE T-MAP is using single-side NIR microscopy, DUAL side WL microscopy and DUAL side NIR microscopy depending on application. A specific open high accuracy stage has been developped to adress 0.1 µm repeatability front to back registration with alignment keys out of the microscope FOV.

    Related products - T-MAP DUAL 3D

  • MEMS in motion dynamic measurement
  • Accurate measurements of MEMS geometries and motions are crucial to achieving the desired performance of the devices. The wide variety of MEMS devices in development and production requires very flexible metrology for single-platform characterization. In addition to having greatly varying geometries, devices must also be characterized under actuation to perform in-plane and out of plane measurement. White-light interferometry, fortunately, is a technique flexible enough to meet most MEMS measurement needs. This high-speed, non-contact measurement method allows both large lateral and vertical ranges with nanometer-level vertical resolution and position accuracy. When standard illumination is replaced with stroboscopic light, dynamic measurements of MEMS can be carried out easily.

    Related products - MEMSOLUTION & 3D Profilers

  • Measurement of devices under controlled atmosphere
    (Vacuum, pressure, Temperature)
  • Stroboscopic interferometric microscopy combined with vacuum box is the perfect tool for MEMS testing, mechanical measurements (quality factor, rising/falling time), and MEMS behavior testing (Reliability) under temperature. Membrane deflection can also characterized by using a pressure environmental chamber.

    Related products - MEMSOLUTION & Environmental Chambers