Ali Javey (Advisor)

Strain state of ultrathin InAs-on-insulator layers obtained from an epitaxial transfer process is studied. The as-grown InAs epilayer (10¨C20 nm thick) on the GaSb/AlGaSb source wafer has the expected ~0.62% tensile strain. The strain is found to fully release during the epitaxial transfer of the InAs layer onto a Si/SiO2 substrate. In order to engineer the strain of the transferred InAs layers, a ZrOx cap was used during the transfer process to effectively preserve the strain. The work presents an important advance toward the control of materials properties of III-V on insulator...

Poly NIPAM (N-isopropylacrylamide) is a kind of thermal responsive polymer that can be synthesized by polymerize NIPAM monomer from its water solution by UV radiation or other synthetic methods. The main impetus to study this material is due to its novel thermal behaviors such as "squeezing out" water from inside, switching from hydrophilic to hydrophobic and changing from transparent to opaque when heating up to its phase transition temperature. Numerous poly NIPAM co- polymers and composites were made to utilize these properties for drug delivery, chemical connectors, and optical...

Semiconductor nanowires have been widely studied for applications such as sensors, photovoltaics, field-effect transistors, and lasers due to their unique physical properties. However, controlling the density and alignment of nanowires over large-area is still challenging for commercial applications. In this project, we plan to design programmable nanowire integration and actuation methods using soft matters. Field-effect transistors and sensing devices will be tested.

Project end date: 08/17/11

We demonstrate ultrathin body (UTB) high mobility InAsSb-on-insulator (XOI) n-FETs. The devices are obtained by the epitaxial layer transfer (ELT) of ultrathin InAsSb layers (thickness, 7-17 nm) onto Si/SiO2 substrates. InAsSb XOI FETs exhibit a peak effective mobility of ~5000 cm2/V-s and an ION/IOFF ratio of over 104. The top-gated devices exhibit an impressive ION of ~0.24 mA/μm (LG~500 nm) at VDD=0.5 V and a SS of ~109 mV/dec. These results demonstrate the utility of the XOI platform for obtaining high mobility n-FETs on Si by using mixed anion arsenide-antimonide as the active...