Atomic Layer Deposition
III-V MBE and Surface Analysis
A modular system integrating two Varian Mod Gen II molecular beam epitaxy (MBE) machines and a Leybold MAX 200 surface analysis facility allows the growth and interface characterization of III-V compound semiconductor heterostructures and nanowires.MBE of III-As nanoheterostructures
One of the Varian Mod Gen II MBE system is equipped with As-cracker source, 2x Ga dual sources. In and Al normal sources. Si and Be are used for doping. The system is used for the growth of a large variety of high quality GaAs/AlGaAs/InGaAs nano-heterostructures necessary for our projects. Additionally, Ga(In) assisted nanowires (NW) incorporating axial and/or lateral heterostructures and controlled doping are grown.
MBE of III-Sb/III-As nanohetrostructures
The second Varian Mod Gen II MBE system is equipped with As and Sb cracker sources, Ga and In dual sources, and Al normal sources. Si and C are used for doping. The system is used to grow III-Sb/III-As type II nanohetrostructures, focusing on resonant tunnelling structures with special properties and field effect transistor structures. Future activities should include the growth of antimonide-based NWs also incorporating axial and/or lateral heterostructures and controlled doping.
Surface analysis of the grown heterostructures is carried out with a Leybold MAX 200 equipment directly connected to the growth systems via an UHV way. The system include XPS, UPS, AES and LEED facilities. The quality of the heterointerfaces and band offsets can be determined. A special interest represents the study of the interface semiconductor/high-k dielectrics (deposited ex-situ by ALD) for our field effect transistor activities. Other materials of interest like topological insulators and graphene are also envisaged to be studied.