III-Nitrides & Arsenides MBE / III-Nitrides & Arsenides Molecular Beam Epitaxy

Molecular Beam Epitaxy (MBE) is a material growth technique, suitable for the fabrication of high-purity semiconductor materials with nano-scale accuracy. Beams of atoms are effused from Knudsen cells in ultra-high vacuum and travel across to impinge on a suitable crystal substrate and form a new layer that has the same crystal structure, and controllable properties. Two different tools are available for the precise growth of semiconductors belonging in (1) the group of III-Nitrides and (2) the group of III-Arsenides.

These tools and associated processes involve heating solid group III elements under ultra-high vacuum to form beams that impinge on the surface of a substrate and form a nearly perfect crystal, binding together with (1) excited Nitrogen atoms emanating from an RF-Plasma source for Plasma Assisted MBE of III-Nitride semiconductors or (2) Arsenic species for MBE of III-Arsenide semiconductors. Several group III materials can be combined, forming alloys with controlled composition. Carrier concentration can, also, be controlled using Si or Mg (1) or Be (2) as a dopant. The grown layers can be arranged, so that nanostructures can be formed with extreme accuracy (thickness resolution less than one monolayer), precise control of all growth conditions and abrupt interfaces.

Typical applications consist of the fabrication of heterojunctions, Quantum Wells (QWs), Quantum Dots (QDs), nanowires, High Electron Mobility Transistors (HEMTs), etc.