Film Metrology in Wafer Inspection
Fast in Position Measurement and Defect Location
For every type of wafer, key prerequisites include uniform substrate and device layer thickness, along with a minimal defect density. Moreover, the wafer's electrical resistivity must closely align with specified standards. Certain films necessitate characterization, especially for assessing thickness, electrical resistivity, and surface quality and roughness. Reliable and fast measurement technologies help to prevent yield losses by detecting defects in an early stage, and thereby reducing costs.
PI is currently developing motion solutions for wafer positioning to facilitate the measurement of crucial wafer attributes.
θ Axis – Fine Rotary Indexing and Alignment of Wafer or Substrate
- Highly accurate and repeatable 360° rotation without backlash
- High velocities and accelerations due to magnetic direct drives
- Direct-drive, slotless, brushless torque motor offers very low cogging torques and enables smooth speed and low error motions
- Ultra-precise air bearings developed and manufactured in house
- Next level performance to further optimize asynchronous performance specifications
>> Technology of Direct Drive Torque Motors
Z Axis – Precision Wafer Alignment
- Low profile, high load, compact superior design
- Direct drive voice coil technology provides zero cogging, smooth motion with nanometer step size and response
- High-resolution encoder for nanometer positioning of the motion platform
- High-precision anti-creep crossed-roller bearings
- Pneumatic counter balance prevent motor heating and prevents collisions
- Economically priced with fast delivery
>> Technology of Direct Drive Motors
XY Axis – Precision Step and Scan Motion
- High-dynamics, ironless linear motors for fast and precise contouring over long travel ranges
- Absolute encoders avoid referencing and ensure safety during operation
- Stiff platform with low profile reduces abbe offsets
- Design allows high flexibility and scalability
- Optimized integrated cable management reduces motion drag and prolongs lifetime
- Granite base ensures highest performance of the motion system
>> Direct Drive Linear Motor Stages
Flexible and Easy Automation Control
- EtherCAT® motion control and drive modules provide open network connectivity
- Advanced algorithms provide fast step-and-settle, high in-position stability, and exceptional constant scanning velocity
>> ServoBoost™ - Extensive programming environment and support for higher level languages
- Autofocus capabilities of the controller for dynamic focus adjustment
- Learning control algorithms
- Compact motion control with linear amplifier performance
