Research / Systems
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== [[GEN III]] == | == [[GEN III]] == | ||
| − | + | This Gen III system is a horizontal reactor with 12 source ports. As of 1/23/2019, the available sources are Ga, In, Al, As, Sb, Er, Si, and Be, which are all solids, and one gas source, CBr4, used for doping. This system is mainly used to grow group III-Vs including aresenides and antimonides. In the past, it was used to research vertical-cavity surface-emitting lasers (VCSELs) and rare earth thermoelectric materials. | |
| + | Currently, this system is used to study quantum dot lasers, micropillars with coupled quantum dots for cavity quantum electrodynamics, and Er:In(Al,Ga)As for THz devices. This Gen III system has an integrated spectrometer for band edge thermometry and in-situ growth rate monitoring. This system belongs to John Bowers' research group. | ||
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| + | [https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.9.031002 Fiber-Coupled Cavity-QED Source of Identical Single Photons] | ||
| + | [https://link.springer.com/article/10.1007/s10762-018-0471-9 Justin Norman's paper on ErAs:In(Al)GaAs Photoconductors] | ||
== [[Spintronics]] == | == [[Spintronics]] == | ||
Revision as of 23:39, 26 February 2019
The UCSB MBE Lab currently has eight operational systems:
Contents |
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
This Gen III system is a horizontal reactor with 12 source ports. As of 1/23/2019, the available sources are Ga, In, Al, As, Sb, Er, Si, and Be, which are all solids, and one gas source, CBr4, used for doping. This system is mainly used to grow group III-Vs including aresenides and antimonides. In the past, it was used to research vertical-cavity surface-emitting lasers (VCSELs) and rare earth thermoelectric materials.
Currently, this system is used to study quantum dot lasers, micropillars with coupled quantum dots for cavity quantum electrodynamics, and Er:In(Al,Ga)As for THz devices. This Gen III system has an integrated spectrometer for band edge thermometry and in-situ growth rate monitoring. This system belongs to John Bowers' research group.
Fiber-Coupled Cavity-QED Source of Identical Single Photons
Justin Norman's paper on ErAs:In(Al)GaAs Photoconductors
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 1/23/2019, the available sources are Ga, In, Al, Mg (p-dopant), Si (n-dopant), and two RF-plasma nitrogen units. One of the plasma sources is used for traditional growth rates of 0.3um/hr, and the other is for growth rates of up to 3 um/hr. There are 3 pumps in the main chamber, 2 cryo pumps and 1 ion pump. The system also has a custom built gas injector for CBr4 and BBr3, which was design and made by John English, making it unique in the world. Some past accomplishments done on this system include: reaching world record mobility for GaN, researching and achieving outstanding GaN/AlGaN HEMTs (high electron mobility transistors) performance, demonstrating growth rates above 7.6 um/hr, and creating the highest structural quality of BGaN using MBE. The Nitride Gen II system is capable of growth rates previously inaccessible to nitride PAMBE (plasma-assisted molecular beam epitaxy) because of its high growth rate plasma unit. It is also capable of growing at low temperatures, which enables high composition InGaN and even pure InN.
This system is currently used for research with James Speck's group and Umesh Mishra's group. The substrates used in this system are GaN on sapphire and free-standing GaN, SiC, ZnO. Current research topics on this system include: growing AlN/AlGaN on SiC for UVLED, reaching high N-flux InGaN for better light emitters and electronics, growing InGaN on ZnO for electronics, and electronics with GaN/AlGaN.
The following are links to important papers based on the work on the system:
Richard Cramer's paper on BGaN
Brian McSkimming's paper on High N-Flux Growth on GaN
Erin Kyle's paper on InAlN Growth
Koblmüller's paper on Growth Modes of GaN
Tarsa's paper on Homoepitaxial growth of GaN
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
This newer Oxide 930 (Veeco) system in the UCSB MBE lab has 8 ports plus a oxygen plasma unit. As of 1/23/2019, the available solid sources are Sr, Ba, Sm, Gd, La, Eu, Ti and Ru. The sources, Ti and Ru, are used to create the organometallic precursors, tetraisopropoxide (TTiP) and ruthenium tetroxide (ZTB), which are advantageous for thin-film growth of metals and metal oxides. This system is currently working with strongly correlated materials, or insulators and electronic materials in the group of heavy fermion compounds. It is primarily used for research in superconductivity and magnetotransport, or the transport of electrons through metals and semiconductors in a magnetic field. This system belongs to Professor Susanne Stemmer's research group.
The following are links to important papers based on the work on this system:
Susanne Stemmer's paper on SrTiO3 Surface Reconstruction in MBE
Susanne Stemmer's paper on Growth of Strontium Ruthenate Films
Oxide 620
The Oxide 620 is a vertical reactor with 6 source ports and a plasma-assisted molecular beam epitaxy (PAMBE) system. As of 1/23/2019, the available solid sources are Ga, Sn, In, Al, and Mg, but they are melted into liquids when operating, except for Mg, which stays as a solid. It also uses a RF-plasma source for oxygen. In the past, this system was used mostly for research of SnO2 (tin oxide) and Ga2O3 (gallium oxide).
Currently, the main growths done on this system are Ga2O3 and metal alloys with Ga, In, and Al. Ga2O3 is a wide band gap semiconductor with the potential of improving power electronics, so these films are grown and analyzed to understand its basic material properties. Other applications of this system include: doping heterostructures and device structures, studying Modulation Doped Field-Effect Transistors (MODFETs). This Oxide 620 system is belongs to James Speck's research group.
The following are links to important papers based on the work on the system:
Elaheh Ahmadi's paper on MODFETs
Min-Ying Tsai's paper on Ga2O3
CdAs GenII
This Gen II system is a horizontal reactor with 8 source ports and is used mainly for Cd3As2 (cadmium arsenide), which is a semi-metal, and other III-V semiconductors. In the past, this system was used for the research and growth of materials such as MgO (magnesium oxide) and Ga2O3 (gallium oxide). As of 1/23/2019, the available sources are Ga, In, Al, Sb, and As. It uses 2 cells for Cd3As2 to get accurate vapor pressure measurements. This system also has Sb and As cracker cells, which produces Sb2 molecules that are used to create buffer layers, ensuring that the surface of the films are stable for growing Cd3As2. The buffer layer can be GaSb (gallium antimonide) or InGaSb (indium gallium antimonide), and it reduces mismatches between the film and substrates that contain some impurities.
This system is capable of growing high qualify films of Cd3As2 and some group III-V materials like GaSb (gallium antimonide). It also has a hydrogen etching system that cleans and prepares substrates, which allows the system to grow with Al materials as well. Currently, this Gen II machine grows Cd3As2 experimentally to research its physical properties because it has the potential to be applied in many areas such as electronics, quantum computers, and infrared detectors. This system belongs to Susanne Stemmer's research group.
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.
