MULTIPROBE MBE SiGe SYSTEM

Multiprobe MBE systems combine state-of-the-art components for MBE growth with a virtually unlimited range of surface analysis instruments. Analytical methods which can be combined with a growth chamber include atomically resolved UHV-STM and AFM for structural analysis, scanning probe spectroscopy (dI/dV) combined SPM/SEM/SAM, structuring and lithography and all common electron spectroscopy techniques such as monochromated XPS for optimum chemical analysis. One example of the capabilities Omicron can offer is the complex MBE and Analysis system installed at the Centre for Quantum Computer Technology, University of New South Wales, Sydney, Australia.

This Multiprobe MBE system is used to prepare Si(100) substrates, using the STM tip to pattern arrays of P-atoms on epitaxially grown passivated Si films, growing high quality overlayers and checking that the dopant atoms haven‘t moved before aligning surface metal electrodes to the buried array. The final goal is to create the first solid state silicon based quantum computer.

The customised Multiprobe MBE was designed with two independent modules: Analysis and MBE. The analysis module is mechanically and acoustically isolated from the MBE module and a bi-directional UHV sample transfer trolley allows samples to be transferred in UHV between the two modules.

The Analysis Module ...
..is equipped with a high resolution STM/SEM microscope for the location of pre-defined sample areas, an independent chamber for sample and tip preparation, AES spectroscopy and a fast entry lock for tip/ sample introduction.

The MBE Module
... ..is designed for the production of 4“ SiGe compound wafers. In addition to the e-beam evaporators for Si and Ge, six spare ports for K-cells are provided. Each evaporator‘s flux is monitored by a quadrupole spectrometer and software controls all growth parameters such as composition, growth rates, doping level and thickness. The growth software is designed for state-of-the-art R&D processes and a recipe editor can produce structural features simply and accurately using a layer/event based structure.