This course will be a detailed study of electron beam evaporation with the end purpose of making quality thin films using this technique.   To do this, we must explore the inner workings of a modern electron beam (e-beam) gun, the thermal, magnetic, and electrical circuits in the e-beam gun, as well as the control systems. Basic hardware and process troubleshooting will also be covered.  This course is designed to interest beginning and advanced users of this technology.

Target Audience: Engineers, technicians, and researchers in vacuum coating, semiconductor, optics, or nanotechnology industries (appropriate for beginners and intermediate users)

Prerequisites: Basic understanding of vacuum technology and physical vapor deposition (PVD) is suggested but not required.

Course Objectives:

  • A working knowledge of how an e-gun works and how it is controlled.
  • Key components and design considerations for e-beam evaporation.
  • Select appropriate materials and deposition parameters for specific applications.
  • Parameters to change to optimize thin film quality.
  • Understand quartz crystal monitors and their use in electron beam evaporation.
  • How to sculpt a process to ensure it runs well and makes the desired film.
  • Basic trouble shooting of e-gun and process.
  • Advantages and disadvantages of electron beam evaporation.

Course Details/Syllabus:

Modern Electron Beam Gun Principles:

  • Beam Generation
  • Beam Sweeping
  • High voltage control
  • Multi Pockets and Pocket Limits for the Beam
  • Thermal Conduction Through the System
  • Electrical Grounding
  • Safety:
    • X-Ray Generation
    • Visible Light Mitigation
    • High Voltage

Rate Control and Quartz Crystal Monitors (QCMs):

Theory Behind QCMs

  • Why is rate control needed?
  • Crystal Head geometry and calibration

Materials and compatibility with Crucible Liners and Hearth Pockets:

  • Metals – problematic materials and strategies
    • Refractory metals strategies
  • Dielectrics – Problems and Strategies
  • Semiconductors – Problems and Strategies

Setting up Materials for a Deposition Run:

  • Recommendations for material sizing
  • Starter Slugs
  • Use of Spacer between crucible liner and hearth pocket
  • Outgassing certain materials before the run

Planning the Deposition Run:

  • Power/ rate calibration done before an official run
  • Setting the final ramp/soak power before going into rate control
  • Helps determine the power ramp up rate
  • Outgassing of the deposition material
  • Choosing an appropriate deposition rate for the material and substrate
  • Cool down of the deposition material after the deposition run

Special Process Requirements:

  • Reactive E-Beam Evaporation
  • Ion gun assist
  • Co-deposition with another source

Troubleshooting an E-Beam Process:

  • Material “core drilling” strategies
  • Rate stability issues
  • Shifting Power over repeated runs with same material
  • Thickness inconsistency
  • Lift-off issues
  • Photoresist interaction with process
  • Rate/Power and substrate exposure to beam
  • Erratic power behavior
  • Filament issues
  • Power supply issues
  • Cable and connection issues
  • Arcing issues
  • Supplementation of Energy to the Substrate
  • Ion Beam-assisted, e-beam evaporation
  • Substrate heat during e-beam evaporation.

Instructor: Rob Belan, Kurt J. Lesker Co.