Theresa J. Hopson

Electrical measurements of a dithiolated electronic molecule via conducting atomic force microscopy

We describe a method of measuring the electrical properties of a molecule via conducting atomic force microscopy (AFM). A dithiolated molecule is chemically inserted into defect sites in an insulating self-assembled monolayer formed on an epitaxial Au substrate and the top thiol terminus of the molecule is reacted with a Au nanoparticle. A Au-coated AFM probe is used to contact the molecule through the nanoparticle, thus electrical data can be obtained. We report preliminary transport measurements of two test molecules. Our data shows qualitative agreement with previously published results for similar molecules deposited in a nanopore containing approximately a thousand molecules. This work indicates that the measured negative differential resistance is not an intermolecular phenomenon.

In situ detection of cytochrome c adsorption with single walled carbon nanotube device

We report on the in situ detection of cytochrome c adsorption onto individual SWNT transistors via the changes in the electron transport properties of the transistors.

Substrate defect smoothing of EUVL mask blanks using TaSiN films

Substrate or phase defects on EUVL masks are considered non- repairable because they lie underneath or are imbedded in the multi-layer mirror. One defect specification requires that no more than three defects greater than 80nm can be present on a starting substrate. Finding and removing these small defects before multi-layer deposition can be very difficult tasks. It has been shown that very small defects can have an influence on the patterned absorber stack and the printed image from an EUVL system. Substrate defect mitigation using TaSiN smoothing layers has been investigated. Programmed Cr defects were formed using standard semiconductor processing techniques and subsequently buried by the defect mitigating film. Experimental results are presented showing that a sputtering process can be used to deposit very smooth and thick TaSiN films (i.e. less than 0.2-nm RMS surface roughness and greater than 1.5-microns thick) as a substrate defect mitigation layer.