The Schottky barrier height (SBH) is mapped with nanoscale resolution at pure Au/Si (001) and mixed Au/Ag/Si(001) interfaces utilizing ballistic electron emission microscopy (BEEM) by acquiring and fitting spectra every 11.7 nm over a 1 µm × 1 µm area. The energetic distribution of the SBH for the mixed interfaces contain several local maximums indicative of a mixture of metal species at the interface. To estimate the composition at the interface, the distributions are fit to multiple Gaussians that account for the species, "pinch-off" effects, and defects. This electrostatic composition is compared to Rutherford backscattering spectrometry (RBS) and x-ray photo-emission spectroscopy (XPS) measurements to relate it to the physical composition at the interface.

Ballistic electron emission microscopy has been utilized to demonstrate differences in the interface electrostatics of tungsten-Si(001) Schottky diodes fabricated using two different deposition techniques: thermal evaporation using electron-beam heating and magnetron sputtering. A difference of 70 meV in the Schottky barrier heights is measured between the two techniques for both p- and n-type silicon even though the sum of n- and p-type Schottky barrier heights agrees with the band gap of silicon. Spatially resolved nanoscale maps of the Schottky barrier heights are uniform for the sputter film and are highly disordered for the e-beam film. Histograms of the barrier heights show a symmetric Gaussian like profile for the sputter film and a skewed lognormal distribution for e-beam film. A Monte-Carlo model is developed to simulate these histograms which give strong indication that localized elastic scattering is causing this skewing as forces the hot electrons to need a greater total energy to surmount the barrier. These differences are attributed to silicide formation from the unintentional substrate heating during the e-beam deposition, which is confirmed with transmission electron microscopy.

A technique to fabricate 5 to 20 nm thick sputter deposited β W films on SiO2 and Si substrates is presented. This is achieved by growing tungsten on a 5 nm SiO2 layer or in an oxygen controlled environment by flowing 2 sccm of O2 during deposition. Resistivity, X-ray photoelectron spectroscopy, X-ray diffraction and reflectivity studies were performed to determine the phase and thickness of tungsten films. These results demonstrate a technique to grow this film on bare Si or a SiO2 substrate, which can enable growth on the bottom of a write unit in a non-volatile spin logic device.

A technique to deposit 5-20 nm thick β-phase W using a 2-second periodic pulse of 1 sccm-N2 gas on Si(001) and SiN(5 nm)/Si(001) substrates is reported. Resistivity, X-ray photoelectron spectroscopy and X-ray reflectivity were utilized to determine phase, bonding and thickness, respectively. X-ray diffraction patterns were utilized to determine the crystal structure, lattice constant and crystal size using the LeBail method. The flow rate of Nitrogen gas (continuous vs. pulsing) had significant impact upon the crystallinity and formation of β-phase W.

A low cost rotatable holder is designed and fabricated for the Quantum Design VersaLab that enables rotation of the device over 90° without the need for rewiring. This allows the magnetic field to be oriented from in plane to perpendicular to plane for the devices, enabling angle dependent measurements. Several measurements are performed to test performance against the standard sample mounting puck that comes with the system. In addition, anomalous Hall measurements are performed on Si|SiO2|Ta (5 nm)|CoFeB (1 nm)|MgO (1.6 nm)|Ta (Cap) devices with the field perpendicular and parallel to the plane of the sample to demonstrate rotation.