Anti-FICD (aa 409-458) polyclonal antibody

The ability to control critical dimensions of structures on semiconductor devices is essential to improving die yield and device performance. As geometries shrink, accuracy of the metrology equipment has increasingly become a contributing factor to the inability to detect shifts which result in yield loss. Scatterometry provides optical measurement that better enables process control of critical dimensions. Superior precision, accuracy, and higher throughput can be achieved more cost effectively through the use of this technology in production facilities. This paper outlines the implementation of Scatterometry based metrology in a production facility. The accuracy advantage it has over conventional Scanning Electron Microscope (SEM) measurement is presented. The Scatterometry tool used has demonstrated repeatability on the order of 3 sigma < 1 nm at STI-Etch-FICD for CD and Trench Depth (TD), and Side Wall Angle (SWA) measurements to within 0.1 degrees. Poly CD also shows 36 < 1 nm, and poly thickness measurement 3 sigma < 2.5 angstrom. Scatterometry has capabilities which include measurement of CD, structure height and trench depth, Sidewall angle (SWA), and film thickness. The greater accuracy and the addition of in-situ Trench depth and sidewall angle have provided new measurement capabilities. There are inherent difficulties in implementing scatterometry in production wafer fabs. Difficulties with photo resist measurements, film characterization and stack set-up will be discussed. In addition, there are challenges due to the quantity data generated; in how to organize and store this data effectively. A comparison of the advantages and shortcomings of the method are presented.

Fic proteins that are defined by the ubiquitous FIC (filamentation induced by cyclic AMP) domain are known to catalyse adenylylation (also called AMPylation); that is, the transfer of AMP onto a target protein. In mammalian cells, adenylylation of small GTPases through Fic proteins injected by pathogenic bacteria can cause collapse of the actin cytoskeleton and cell death(1,2). It is unknown how this potentially deleterious adenylylation activity is regulated in the widespread Fic proteins that are found in all domains of life and that are thought to have critical roles in intrinsic signalling processes. Here we show that FIC-domain-mediated adenylylation is controlled by a conserved mechanism of ATP-binding-site obstruction that involves an inhibitory alpha-helix (alpha(inh)) with a conserved (S/T)XXXE(G/N) motif, and that in this mechanism the invariable glutamate competes with ATP gamma-phosphate binding. Consistent with this, FIC-domain-mediated growth arrest of bacteria by the VbhT toxin of Bartonella schoen-buchensis is intermolecularly repressed by the VbhA antitoxin through tight binding of its alpha(inh) to the FIC domain of VbhT, as shown by structure and function analysis. Furthermore, structural comparisons with other bacterial Fic proteins, such as Fic of Neisseria meningitidis and of Shewanella oneidensis, show that alpha(inh) frequently constitutes an amino-terminal or carboxy-terminal extension to the FIC domain, respectively, partially obstructing the ATP binding site in an intramolecular manner. After mutation of the inhibitory motif in various Fic proteins, including the human homologue FICD (also known as HYPE), adenylylation activity is considerably boosted, consistent with the anticipated relief of inhibition. Structural homology modelling of all annotated Fic proteins indicates that inhibition by alpha(inh) is universal and conserved through evolution, as the inhibitory motif is present in similar to 90% of all putatively adenylylation-active FIC domains, including examples from all domains of life and from viruses. Future studies should reveal how intrinsic or extrinsic factors modulate adenylylation activity by weakening the interaction of alpha(inh) with the FIC active site.