EpiRAS® TT: unmatched surface interface sensitivity

EpiRAS® TT is a multipurpose in-situ monitor of epitaxial growth of cubic semiconductors. The system combines two spectroscopic optical techniques: Reflectance Anisotropy Spectroscopy (RAS), sometimes called Reflectance Difference Spectroscopy (RDS), and spectroscopic reflectance (sR), as well as Emissivity Corrected Pyrometry.


EpiRAS® TT is a research tool that provides data on wafer temperature, growth rate, colorplot (RAS/sR) fingerprints, composition, morphology, doping levels.


EpiRAS® TT can be adapted to almost any growth system. We have extensive experience with integrating EpiRAS® TT into MOCVD and MBE reactors. Please contact sales@laytec.de for detailed information and suggestions for your specific growth needs.


To see LayTec in-situ metrology live, you can watch a video that we have taken at a customer site. In a short lab tour at FBH Berlin in Germany you will see how EpiCurve® TT and EpiRAS® TT monitor LED and laser growth and help optimize the processes. ... more


EpiRAS® TT is an ideal tool for development of concentrator solar cells (CPV). In multi-junction solar cell development, the metrology system helps to control key growth parameters of heterostructures throughout MOCVD process, to avoid initial antiphase boundary formation at the III-V of Ge interface, to determine the ternary composition, interface quality, growth rate and doping level of the structure. Learn more in our CPV Application Note


Product information

Fields of application:

  • Growth of cubic semiconductors like III-As and P
  • R&D for new materials and devices

     and many others.

Product features:

  • Full spectroscopic wafer selective RAS and reflectance measurements at 280 nm - 800 nm
  • Spectroscopic and time-resolved pseudo 3D color plot
  • True reflectance measurements
  • Wafer-selective growth rate fits
  • Features of EpiTT can be included (EpiRAS® TT)