Motors and Actuators for Semiconductor Equipment

Sierramotion Application Solutions

This sector is typically referred to as semiconductor front end processing. The applications involve rotating wafers during processing and inspection or moving reticles in the case of photolithography. There is also a wide range of optical and light/laser systems that need beam positioning, conditioning, and collimation. Motors and actuators are used, along with precision encoders and control systems, to precisely position mechanical systems to micron level accuracy with nanometer level resolution. The front-end processing also involves special environments and materials.

Deep vacuum is common, and the use of non-corrosive materials and low out gassing materials is also typical. Under these conditions it is normal to laser weld an enclosure around the motor parts to hermetically seal them from outgassing. Environments with many optical parts commonly use a hydrogen purge or low level of hydrogen is always present. Hydrogen and magnets do not normally play well together, so a hermetic enclosure may be required for any motor with magnets (which is most motors in the precision motion space).

Wafer/reticle handling and positioning systems

Voice Coil Linear Actuator

Voice Coil linear actuators and actuator assemblies

Designed for use in deep vacuum or atmosphere, voice coil linear actuators include laser welded hermetically sealed enclosures around coils and magnets and any bearing system appropriately selected with correct grease.

Thermal modeling of the complete system is required if the motion is in vacuum due to the lack of convection. All motor and actuator products need to be derated and modeled for thermally to arrive at a new temperature rating.

Z-Drive Ball Screw Actuator

Z-Drive ball screw actuators

Precision highly integrated direct driven balls screws for lifting local platforms for processing and inspection. These applications can use linear motors if the loading is light <100 Newtons, but otherwise with higher loading the ball screw is most effective.

Special greases are required for clean room operation and more specific details are required if the motor driven actuator is used in vacuum.

Linear Motors

Linear motors and liner arc shaped motors

Linear travel for wafer/reticle handling takes on two forms. There is a macro level of motion covering changes from one process to another. There is also a micro level of motion to align optics and other sensors at the micron level once the process starts.

Many optical systems need beam collimation and conditioning, in the form of polarizing and analyzing, this can be done by a series of actuators and hollow shaft motors and associated high resolution encoders can be designed to make these critical movements.

Direct Drive Motors

Direct drive rotary motors and stages

These motors are designed for large through hole (aperture) so that optics and possible other items can fit through the inside of the motor. High resolution encoders are used that offer more than 22 bit resolution and micron level accuracy with nanometer level resolution.

Optical system scanning and positioning

  • Micro-linear motors with travel in mm and accuracy in microns
  • Voice coil motors and actuators with precision movement
  • Voice coil motors with air bearings for high precision mechanical and electrical movements
  • Optics positioning and scanning
  • Theta motion for polarizing
  • Line of sight lens optimization with precision angle movement
  • Large aperture for internal lenses
  • Precision movement at with high resolution to 1-10 arc-second range
  • Micro-linear motors with travel in mm and accuracy in microns.
  • Voice coil motors and actuators with precision movement
  • Voice coil motors with air bearings for high precision mechanical and electrical movements
  • Optics positioning and scanning
  • Theta motion for polarizing
  • Line of sight lens optimization with precision angle movement
  • Large aperture for internal lenses
  • Precision movement at with high resolution to 1-10 arc-second range

EUV deep vacuum robots and actuators

  • Alignment and tilt of platforms using hybrid VCM technology
  • Magnetic gravity compensation
  • High force and high accuracy
  • Dual encoder feedback
  • Accuracy to < 1 micron, resolution to 20 nanometers
  • Drive drive motors attached directly to the ball screw for high bandwidth and elimination of low stiffness couplings
  • Reticle and Wafer movement for rapid cycling of exposure in photolithography
  • Precision movement with high resolution
  • Internal direct drive torque motors operating at 24 volts.
  • Precision mechanical bearings
  • Air bearings
  • Low profile to fit into tight spaces
  • Zero cogging
    • Alignment and tilt of platforms using hybrid VCM technology
    • Magnetic gravity compensation
    • High force and high accuracy
    • Dual encoder feedback
    • Accuracy to < 1 micron resolution to 20 nanometers
    • Drive drive motors attached directly to the ball screw for high bandwidth and elimination of low stiffness couplings
    • Reticle and Wafer movement for rapid cycling of exposure in photolithography
    • Precision movement with high resolution
    • Internal direct drive torque motors operating at 24 volts.
    • Precision mechanical bearings
    • Air bearings
    • Low profile to fit into tight spaces
    • Zero cogging

    Other Applications

    • Motors and actuators working through a vacuum chamber wall
    • Magnetic bearings and magnetic couplings working partially in vacuum
    • High torque direct drive motors for CMP load optimization
    • Sealed construction for harsh environments with CMP polishing materials.
    • High efficiency at low speed to for optimized performance and size for CMP machinery.
    • Large through hole to fit around cleaning drum
    • Modular construction moving magnet ring motor for direct drive of drum
    • Special linear motors for operating accessories
    • Motors and actuators working through a vacuum chamber wall
    • Magnetic bearings and magnetic couplings working partially in vacuum
    • High torque direct drive motors for CMP load optimization
    • Sealed construction for harsh environments with CMP polishing materials.
    • High efficiency at low speed to for optimized performance and size for CMP machinery.
    • Large through hole to fit around cleaning drum
    • Modular construction moving magnet ring motor for direct drive of drum
    • Special linear motors for operating accessories

    Electronics Assembly and Packaging

    Pick and Place Machine

    Pick and Place Components

  • Linear motors highly integrated into mechanical parts
  • Halbach array motors for higher through put and peak force
  • Modular magnet tracks for long travel
  • High natural resonance frequency for high gain systems and fast settling time
  • Positioning Systems

    Positioning Systems

  • Motors with precision magnetic fields for minimum hysteresis and eddy currents allowing higher bandwidths
  • Linear torque output with current for higher bandwidth and high peak currents
  • Zero cogging for minimum torque ripple
  • Optical Inspection

    Inspection (Optical/Mechanical)

  • High resolution precision positioning with zero cogging and low torque ripple
  • < 1% harmonic distortion of the torque output with current and angle
  • Wire Bonding

    Packaging / Wire Bonding

  • Rapid acceleration motors with key features for wire bonding
  • Modular construction for deep integration with other mechanical parts.