Research / Systems

Revision as of 23:15, 26 February 2019

The UCSB MBE Lab currently has eight operational systems:

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 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: [https://aip.scitation.org/doi/10.1063/1.4901726 Susanne Stemmer's paper on SrTiO3 Surface Reconstruction in MBE] [https://aip.scitation.org/doi/10.1063/1.4998772 Susanne Stemmer's paper on Growth of Strontium Ruthenate Films] 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 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.