Selective electroless metallization of patterned polymeric films for lithography applications

The fabrication of electrical interconnects to provide power for and communication with computers as their component complementary metal oxide semiconductor (CMOS) devices continue to shrink in size presents significant materials and processing compatibility challenges. We describe here our efforts to address these challenges using top-surface imaging and hybrid photoresist/self-assembled monolayer patterning approaches, in conjunction with selective electroless metal deposition, to develop processes capable of fabricating appropriate submicron and nanoscale metal features useful as electrical interconnects, as well as plasma-etch-resistant masks and metal diffusion barriers. Our efforts focus on the development of cost-effective methods compatible with a manufacturing environment that satisfy materials and process constraints associated with CMOS device production. We demonstrate the fabrication of approximately 50-nm-width features in metal with high fidelity and sufficient control of edge acuity to satisfy current industry design rules using our processes and discuss the challenges and opportunities for fabrication of analogous sub-10-nm metal features.

Chitosan-pentaglycine-phenylboronic acid conjugate: a potential colon-specific platform for calcitonin

Novel drug delivery vehicles based on the biodegradable, mucoadhesive polysaccharide chitosan covalently linked to a boronic acid protease inhibitor have been prepared and characterized. It was anticipated that these conjugates could protect a proteinaceous drug, such as salmon calcitonin, against proteolysis by serine proteases, an obstacle that prevents its oral administration. Specifically, 4-formylphenylboronic acid was linked to chitosan. Three types of conjugates were prepared. In the first, 4-formylphenylboronic acid was directly linked to chitosan. The other two conjugates employed glycylglycine and pentaglycine spacers. Enzyme-inhibition assays toward trypsin and elastase, in the presence of the enzyme chitosanase, demonstrated a strong inhibitory effect for the chitosan-pentaglycine-phenylboronic acid conjugates, while no inhibitory effect could be detected without chitosanase. The chitosan-pentaglycine-phenylboronic acid conjugate with the highest degree of substitution of 4-formylphenylboronic acid was able to decrease the salmon calcitonin degradation rate by trypsin. It is concluded that chitosan-pentaglycine-phenylboronic acid conjugates are a potential multifunctional, colon-specific vehicle for orally administered salmon calcitonin.