Research / Systems
The UCSB MBE Lab currently has eight operational systems:
Contents |
System A
As of 2007 System A has been converted to a metal organic molecular beam epitaxy machine (MOMBE). It is fitted with 4 sources. System A is used to grown SiErO structures which are engineered to emit at the 1.55um wavelength range.
System C
System C is a horizontal reactor with 8 ports plus a dual gas injector/pyrometry port. As of 3/3/2008, available materials are: Al, Ga, In, Er, As, Sb, Si, Be, and CBr4. In addition, there is an e-beam evaporation chamber attached under UHV, allowing the deposition of thin films of Mo and possibly W. A thermally cracked hydrogen station allows desorption of native oxides from GaSb and similar wafers without melting them.
Recent activity on System C includes: ErAs nanoparticles and films on GaAs and InGaAs for physics, tunnel junctions, and thermoelectrics, High-mobility channels for InGaAs MOSFETs are also grown on this machine, as are record low resistance ohmic contacts to InGaAs and InAs for next-generation MOSFETs and HBTs.
GEN III
The GEN III has 12 sources.
Spintronics
Spintronics is an Applied Epi (Veeco) Gen II horizontal reactor with 8 ports plus a band-edge thermometry/pyrometry port. As of 10/24/2008, available materials are: Al, Ga, In, Mn, As, Cr, Si, and Be. The transmission band-edge thermometry system allows for accurate, reproducible control of the substrate temperature 400° below normal; this capability is useful for highly non-equilibrium growth of alloys such as GaMnAs, a ferromagnetic semiconductor.
Recent activity on Spintronics includes: optical studies of quantum-confined GaMnAs in the far-paramagnetic regime and studies of bulk (~100 nm) films of GaMnAs in the far-ferromagnetic regime.
Nitride GEN II
The plasma nitride system is a Varian Gen II horizontal reactor with 8 source ports plus a pyrometry port. As of 12/12/2008, the available source materials are Ga, Al, In, Si (n-dopant), a dual dopant cell/gas injector for Mg(p-dopant)/CBr4(for semi-insulating buffers), and two RF-plasma nitrogen sources. Unlike most other compound semiconductors, a metal-rich surface is necessary for the the MBE-growth of group-III nitrides to achieve smooth surface morphology and low impurity incorporation under typical growth conditions below the decomposition limit of GaN. We recently acquired a nitrogen source which offers very high growth rates (a few microns/h) and hence enables much higher growth temperatures without the need to maintain a metal adlayer. A quadruple mass spectrometer can be installed into one of the source ports for in-situ monitoring of growth dynamics.
This system has been the primary tool for the rich research of MBE-grown III-N materials and devices at UCSB. AlGaN/GaN high electron mobility transistors (HEMTs) with outstanding high frequency performance have been fabricated on materials grown in this system. Recent activities on this system include: N-rich/high-temperature GaN growth, N-polar GaN HEMTs, GaN on silicon substrates, solar cells, polarization-doped tunnel junctions for LED devices, and devices on non-polar nitride epilayers.
Nitride 930
Quick summary of Nitride 930. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus sem. Curabitur placerat adipiscing ante. Praesent lobortis justo sit amet dolor. Sed tincidunt. Cras justo velit, gravida ac, mollis a, dignissim et, enim. Curabitur luctus purus ut orci. Fusce dapibus massa in enim. Suspendisse sit amet metus. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; In vel diam ut libero egestas placerat.
Oxide 930
Quick summary of System C. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus sem. Curabitur placerat adipiscing ante. Praesent lobortis justo sit amet dolor. Sed tincidunt. Cras justo velit, gravida ac, mollis a, dignissim et, enim. Curabitur luctus purus ut orci. Fusce dapibus massa in enim. Suspendisse sit amet metus. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; In vel diam ut libero egestas placerat.
Oxide 620
The Oxide 620 is a vertical reactor with 6 source ports and currently 5 sources. The 5 sources are Sn, In, Sb, Ga, and an oxygen rf-plasma source.
VG V80H III-V/Metals
The Oxide 620 is a vertical reactor with 6 source ports and currently 5 sources. The 5 sources are Sn, In, Sb, Ga, and an oxygen rf-plasma source.
Metals
The Oxide 620 is a vertical reactor with 6 source ports and currently 5 sources. The 5 sources are Sn, In, Sb, Ga, and an oxygen rf-plasma source.
Heusler GEN II
The Oxide 620 is a vertical reactor with 6 source ports and currently 5 sources. The 5 sources are Sn, In, Sb, Ga, and an oxygen rf-plasma source.
Veeco Oxide
The Oxide 620 is a vertical reactor with 6 source ports and currently 5 sources. The 5 sources are Sn, In, Sb, Ga, and an oxygen rf-plasma source.
