Epi-growth and monitoring

Growth tool

The Veecco GEN10 molecular beam epitaxy (MBE) system is a cluster tool with the ability to hold up to 3 reactors. At the moment the tool is configured with one reactor for (Al, Ga, In)III(As,Sb)V materials and substrates with diameters of up to 3”. With Veeco's comprehensive and integrated Molly® growth control and Lot Manager™ scheduling software packages, the system can be operated 24/7. The tool installed in the Quantum Nano Centre Molecular Beam Epitaxy lab is also equipped with a plasma chamber for wafer surface preparation.

qncmbe1

In-situ growth monitoring

Monitoring of the growth process is key for achieving high quality structures that can be used in high performance device production and to enable good understanding and design of new epi-processes. Our MBE facility is equipped with top of the line instruments for growth monitoring:

Absorption/transmission band edge changes with temperatureBand-edge thermometry (BET)

Wafer temperature monitoring using the temperature-dependent optical absorption edge inherent in semiconductor materials.

Eg(T) = Eg(0) - αT2/(T+β)

Reflectivity and reflectance corrected pyrometryreflectance changes with epilayers composition

Analysing the reflectance anisotropy signal during growth provides insight into:

  • Quality of this epilayers
  • Real time growth rates
  • Wafer temperature

Reflection high energy electron diffraction (RHEED)

RHEED imageMonitoring the diffraction pattern of high-energy electrons ejected from the surfaces provides information about:

  • Epilayer thickness
  • Growth rate
  • Surface roughness
  • configuration of the surface (reconstruction processes)
  • Surface kinetics (evolution of surface over time)

Residual gas analysis (RGA)RGA signal of He during leak test

  • Mass spectrum analysis allow for surface chemistry and kinetics studies
  • Testing the system for leaks

Beam flux monitor signal at different conditions of Al effusioncellIon gauges

  • Control of vacuum conditions
  • Calibrations of the molecular fluxes

reflectance changes with epilayers composition