|
Research Facility
Riber EPI-2300 MBE system 
Function:
The Riber EPI-2300 Molecular Beam Epitaxy (MBE) system is used for the
growth of device-quality HgCdTe epilayers on both CdZnTe and CdTe/Si substrates. This system
is equipped with an in-situ Reflection of High-Energy Electron
Diffraction (RHEED) analysis system which is employed to
monitor the epilayer growth. The system also offers an in-situ
reflection-mode Fourier Transformation Infrared (FTIR) pyrometer to
control the x-value of the HgCdTe epilayer (composition of the group II elements) and exactly measure
the substrates' temperatures.
The Riber EPI-2300 is one of four Molecular Beam Epitaxy (MBE) chambers at
the MPL. This chamber stands alone, due to high Hg flux and contamination
issues.
Research:
The Riber EPI-2300 MBE system is used in research projects such as these:
- P-type doping
- Nucleation study
- Dislocation and voids density reduction
- Growth of infrared detector structure
These research projects enable the growth of high-quality HgCdTe p-n
junctions for infrared detectors.
Specifications:
The MBE chamber is fully equipped with:
- eight conventional knudson effusion cells
- a continuous feeding Hg cell, which produces a highly stable Hg
flux
- a mass spectrometer
- RHEED
- in-situ FTIR
The flux from the effusion cell can be
interrupted with ease using the small shutters available for each effusion
cell. This setup thus makes it possible to fabricate highly sophisticated
artificial materials and structures such as:
- quantum well structures
- superlattices
- hetero/homo structures
- with abrupt interfaces
- with graded interfaces
The main shutter can block the molecular flux from all the effusion cells
and is very important during substrate surface preparation before
epitaxial growth. The growth in the system is closely monitored by high
energy electron diffraction using a 50 keV RHEED gun. The molecular flux
is measured by an ion gauge. Photo-assisted MBE growth is performed using
an Ar ion laser.
|
|
|
