Facilities

Growth

Omicron MBE-STM

Operational since 2008. This MBE system grows on 11.8x11.4 mm square samples. Although the small sample size is a drawback for material characterisation, it is economical as up to 10 samples can be cleaved from a single 2" wafer. The system can achieve high sample uniformity, despite having no sample rotation during growth. Temperature measurement of the substrates is done using RHEED transitions.

Effusion Cells:

Ga (MBE Komponenten WEZ40)

Al (MBE Komponenten WEZ40)

In (MBE Komponenten WEZ40)

As2 / As4 valved cracker (Veeco valved cracker for arsenic 500cc)

Si + Be dual dopant source (MBE Komponenten DCS63)

Bi (MBE Komponenten NTEZ63)

Measurement and Control:

RHEED (Staib), custom RHEED software

2x Ion gauge (Epimax, AML)

FEL wide range gauge (Pfeiffer)

Vacuum system:

MBE chamber: ultimate pressure ~5e-10 mBar

Turbo pump (Pfeiffer), backed with rotary vane pump (Edwards RV3), ion pump (Varian VacIon Plus 300 Starcell), TSP, cryo-shroud (LN2 at -90 oC, fed from 400 L dewar)

STM chamber: ultimate pressure ~3e-11 mBar

Turbo pump (Pfeiffer TMU 261), backed with rotary vane pump (Edwards RV5), ion pump (Varian), TSP

FEL chamber: ultimate pressure ~8e-8 mBar

Turbo pump (Pfeiffer HiPace 80), backed with scroll pump (Agilent TriScroll 300)

VG V80 MBE

This MBE system was originally installed at Imperial College London in the late 1980s, before being kindly donated to Sheffield University in August 2016. The system is currently being installed in its new home in the nanoscience and technology centre.

Effusion Cells:

In dot

In well

Measurement and Control:

Mass spectrometer

Pyrometer

RHEED

Ion gauges

Vacuum system:

Growth chamber:

Preparation chamber:

FEL chamber: