Thermal Laser Epitaxy

Thermal laser epitaxy is a physical vapor deposition technique. It uses single element sources that are heated by lasers beams in order to thermally evaporate the source material. Because the laser beams can be made with almost arbitrary power density, extremely high temperatures are possible. This allows for the evaporation of practically all elements of the periodic table with the same setup. Therefore, TLE is a very versatile deposition technique. Because the energy sources are placed outside the vacuum chamber, the chamber requires only simple holders for the sources and substrates. This benefits system simplicity and sample purity. Moreover, the direct local heating of targets in TLE ensures that only the evaporating surfaces are heated (see the tantalum example). This minimizes contamination. TLE is compatible with a range of background gasses up to pressures of 10-2 mbar. In summary, TLE is a highly flexible deposition technique that can be used to grow almost any material with high purity.

TLE is especially interesting for materials science in the fields of quantum computing, strongly correlated electron systems, novel material synthesis, topological materials, and energy research.


Advantages of TLE

  • Almost all elements possible (including high-T melting materials)
  • High purity
  • Low energy deposition due to thermal evaporation
  • Easy source and sample transfer
  • Highly different materials can be used on a daily basis (daily material change possible!)
  • High throughput (very fast ramping of the sources)
  • Robust with high uptime (simple vacuum system, high vacuum quality, simple source insertion/extraction)
  • Low operating cost (low kW consumption, high target utilization, high throughput, easy to substitute/upgrade chambers)
  • Multiple background gasses possible
  • Excellent combinatorial synthesis
  • Excellent composition gradients
  • Multilayer growth
  • High-quality raw materials available
  • Large-scale substrate size (50-300 mm) possible
  • Multiple chambers can be operated with one set of lasers : cost efficient to run multiple research projects in parallel
  • Growth analysis by RHEED


Technical challenges in TLE

TLE has some intrinsic challenges as well. Based on our long experience with TLE setup we have developed patent-protected solutions for:

  • Growth stability
  • Uniform melting of the sources
  • Entrance window protection
  • Combining sources with high and low temperatures

TLE benefits compared to traditional technologies