The current transport mechanism in non-annealed Ohmic contact metallizations on p-type 6H-SiC formed by using focused ion beam (FIB) surface-modification and direct-write metal deposition is reported, and the properties of such focused ion beam assisted non-annealed contacts are discussed. The process uses a Ga focused ion beam to modify the surface of the semiconductor with different doses, and then introduces an organometallic compound in the Ga ion beam, to effect the direct-write deposition of a metal on the modified surface. Contact resistance measurements by the transmission line method produced values in the low 10-4 Ω cm2 range for surface-modified and direct-write Pt and W non-annealed contacts, and mid 10-5 Ω cm2 range for surface-modified and pulse laser deposited TiN contacts. The current transport mechanism of these contacts was examined and found to proceed mainly by tunneling through the metal-modified-semiconductor interface layer.

A ZnO/Zn0.8Mg0.2O double barrier resonant tunneling device (DBRTD) is reported here for the first time. The structure consists of 6 nm ZnO quantum wells and 7 nm Zn0.8Mg0.2O barriers grown by pulsed laser deposition (PLD) on c-cut sapphire substrates. Negative differential resistance (NDR) peaks were obtained at room temperature. The structure is developed by using an indium-tin oxide (ITO) layer both as the back contact electrode and as an etch-stopping layer. The PLD growth quality, wet etching processing for developing the mesa structure, and the I-V characteristics of the device are reported.

The synthesis of self-assembled ZnO nanostructures at room temperature using a microphase separated diblock copolymer as a template is reported. Poly(norbornene) / poly(norbornene-dicarboxylic acid) diblock copolymers were synthesized using Ring Opening Metathesis Polymerization (ROMP). The polymers were dissolved and the solutions were doped with ZnCl2. Films were formed from this solution, and subsequently reacted with NH4OH. This converted the ZnCl2 into ZnO contained within the microphase-separated nanodomains of the block copolymer. Fourier Transform Infrared Spectroscopy verified the association of the metal to the second block of the polymer, and X-ray Photoelectron Spectroscopy verified the conversion of the salt to ZnO nanoclusters. The development of such ZnO - block copolymer nanocomposites is targeting the functionalization of nanostructures into device technologies.