Adsorption of short-chain tetraalkylammonium bromide on silica

The adsorption of tetraalkylammonium (TAA) ions on silica shifts the isoelec. point to higher pH values. The IEP shift increases with increasing alkyl chain length. Also, tetraethylammonium (TEA) and tetrapropylammonium (TPA) ions can be adsorbed in larger amts. than tetramethylammonium (TMA) ions. The chemisorption of TAA ions can be explained by assuming an attraction between hydrophobically hydrated regions around surface siloxane bridges and around the TAA ions. The adsorption data of TMA ions are compatible with the stimulated adsorption model. [on SciFinder (R)

Enhancing re-detection efficacy of defects on blank wafers using stealth fiducial markers

To qualify tools of semiconductor manufacturing, particles unintentionally deposited in these tools are character-ized using blank wafers. With fast optical inspection tools one can quickly localize these particle defects. An ex-ample is TNO's Rapid Nano, which operates in optical darkfield. The next step is defect review for further defectcharacterization. When the blank wafers are transferred to another tool, e.g. a SEM or an AFM the absolute defectposition information is lost. Therefore, the re-detection of the defects in the review tool is time consuming. Toenhance the re-detection speed, afiducial marker system can be used that couples the coordinates of the fastinspection tool to the coordinates of the characterization (review) tool.In this work such afiducial marker system was designed and validated. The influences of the height and the com-position of thefiducial markers on the performance of the marker system were investigated usingfinite elementanalysis (by COMSOL) and experiments. The optimizedfiducial markers are very visible in opticalbrightfield andin SEM, while almost invisible (“stealth”) in optical darkfield. These properties make the markers both easily vis-ible and accurately localizable in the characterization tools. The stealthfiducialmarker system was fabricatedandvalidated by re-detecting programmed test defects on a blank wafer. The experimental results are compared to aMonte Carlo simulation that takes into account the uncertainties in the coordinate transformation and localiza-tion of the test defects.Our results show that afiducial marker system greatly enhances the re-detection efficacy of defects on blank wa-fers. Using thefiducial marker system, 100% of the test defects were re-detected in SEM and AFM. A single7×7μm2SEM image suffices to meet the ITRS requirement for particles as small as 70 nm in diameter

Method and system for forming a metallic structure

Method of forming a metallic structure (2) in a micro-machined recess that is provided in a surface of a semiconductor substrate (8). The method comprises positioning a protrusion (10) of an apparatus for depositing the metallic structure at least partly inside the recess, thus partly occupying the recess with the protrusion and defining in the recess a gap (14) along the protrusion. The method comprises driving a deposition fluid (20) through the gap in the recess along the protrusion. The method comprises growing in the gap the metallic structure by depositing metal ions contained by the deposition fluid. The method comprises moving the protrusion and the substrate relative to each other so that the protrusion, while being positioned in the recess, moves relative to the recess in a direction out of the recess, thus giving way for the growing of the metallic structure, and forming the metallic structure in the recess

Enhancing re-detection efficacy of defects on blank wafers using stealth fiducial markers

To qualify tools of semiconductor manufacturing, particles unintentionally deposited in these tools are character-ized using blank wafers. With fast optical inspection tools one can quickly localize these particle defects. An ex-ample is TNO's Rapid Nano, which operates in optical darkfield. The next step is defect review for further defectcharacterization. When the blank wafers are transferred to another tool, e.g. a SEM or an AFM the absolute defectposition information is lost. Therefore, the re-detection of the defects in the review tool is time consuming. Toenhance the re-detection speed, afiducial marker system can be used that couples the coordinates of the fastinspection tool to the coordinates of the characterization (review) tool.In this work such afiducial marker system was designed and validated. The influences of the height and the com-position of thefiducial markers on the performance of the marker system were investigated usingfinite elementanalysis (by COMSOL) and experiments. The optimizedfiducial markers are very visible in opticalbrightfield andin SEM, while almost invisible (“stealth”) in optical darkfield. These properties make the markers both easily vis-ible and accurately localizable in the characterization tools. The stealthfiducialmarker system was fabricatedandvalidated by re-detecting programmed test defects on a blank wafer. The experimental results are compared to aMonte Carlo simulation that takes into account the uncertainties in the coordinate transformation and localiza-tion of the test defects.Our results show that afiducial marker system greatly enhances the re-detection efficacy of defects on blank wa-fers. Using thefiducial marker system, 100% of the test defects were re-detected in SEM and AFM. A single7×7μm2SEM image suffices to meet the ITRS requirement for particles as small as 70 nm in diameter.HarvestQN/Kavli Nanolab Delf

Method and apparatus for depositing atomic layers on a substrate

\u3cp\u3eMethod of depositing an atomic layer on a substrate. The method comprises supplying a precursor gas from a precursor-gas supply of a deposition head that may be part of a rotatable drum. The precursor gas is provided from the precursor-gas supply towards the substrate. The method further comprises moving the precursor-gas supply by rotating the deposition head along the substrate which in its turn is moved along the rotating drum. The method further comprises switching between supplying the precursor gas from the precursor-gas supply towards the substrate over a first part of the rotation trajectory; and interrupting supplying the precursor gas from the precursor-gas supply over a second part of the rotation trajectory\u3c/p\u3

Method and apparatus for depositing atomic layers on a substrate

Method of depositing an atomic layer on a substrate. The method comprises supplying a precursor gas from a precursor-gas supply of a deposition head that may be part of a rotatable drum. The precursor gas is provided from the precursor-gas supply towards the substrate. The method further comprises moving the precursor-gas supply by rotating the deposition head along the substrate which in its turn is moved along the rotating drum. The method further comprises switching between supplying the precursor gas from the precursor-gas supply towards the substrate over a first part of the rotation trajectory; and interrupting supplying the precursor gas from the precursor-gas supply over a second part of the rotation trajectory