EPSRC Electron Beam Epitaxy (EBE)
Electron Beam Epitaxy is a new method for the deposition of thin films of functional and electronic device materials. The technique uses an electron beam to heat solid pieces of individual elements or compounds in an ultra-high vacuum, evaporating them onto a substrate. EBE holds several advantages over other thin film deposition techniques, namely:
- A very wide range of elements and compounds can be evaporated, since evaporation from multiple electron beam sources is possible and a higher temperature can be achieved than with conventional thermal techniques
- Very pure films due to direct transfer of heat from the electron beam to the material, with little heating of the surrounding areas
- Precise control of film thicknesses and compositions through accurate control of the electron beam and shutters
The possibility of achieving very uniform material deposition by control of the relative target-substrate distances and angles
We have two ultra-high vacuum systems for EBE: one is dedicated to nitride film growth, the other to oxide film growth. Both systems were custom built by Mantis Deposition, and they are situated within the Thin Film Technology laboratory.
The Nitrides system comprises a main chamber equipped with three electron beam sources, in situ high-energy Reflection High Energy Electron Diffraction (RHEED), an in-situ energy-dispersive X-ray spectrometer, RF atom source (nitrogen) and a substrate table controller. Samples can be transferred into an adjoining chamber which houses a Raman spectrometer without the need to break UHV conditions. Up to five samples can be loaded at once via the load lock chamber.
The Oxides system consists of a main chamber furnished with two electron beam evaporators, in situ RHEED, RF atom sources (both oxygen and nitrogen), and a substrate table controller. Up to five samples can be loaded at once via the load lock chamber.
- Electron beam evaporators: Mantis, up to 10 kW capability
- Substrate table heating capable of reaching 1000 °C
- RHEED: Staib RHEED 50, 50 keV electron source
- Raman: Horiba LabRAM HR evo with 532 and 785 nm lasers
The equipment is generously funded by the EPSRC through which we invite collaboration, both academic and industrial.