Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Attitude estimation of the Delfi-n3Xt satellite

This paper presents current developments of the attitude determination algorithm for Del¦-n3Xt, TU Delft next nanosatellite. Several novel quaternion filters using Sun vector and Earth magnetic field measurements and rate gyro outputs are presented. The quaternion measurement matrix associated with each line-of-sight measurement is shown to be rank deficient. This property is exploited in order to design reduced order measurement update stages in the filters. The measurement model reduction is designed such as to preserve the statistical information. The filter covariance propagation can cope rigorously with the multiplicative process noises. The paper also describes the development of the Sun vector determination algorithm, which merges the outputs of 6 body-mounted four-quadrant Sun sensors. For each sensor, a simple algorithm allows Sun vector determination while avoiding the use of uncertain physical parameters. This algorithm takes into account geometrical imperfections linked to manufacturing limitations. A thorough error analysis of the photodiodes measurement outputs is carried out. A spacecraft Sun vector determination algorithm is proposed and illustrated, in the absence of Earth albedo effect, via Monte-Carlo simulations and experimental validation. In addition, extensive Monte-Carlo simulations illustrate the good performances of the quaternion filters using spacecraft Sun vector and Earth magnetic field measurements. The novel reduced filter shows good performances in a challenging tumbling dynamics environment, where a standard additive Kalman filter fails to converge.Space EngineeringAerospace Engineerin

Model for nanopillar growth by focused helium ion-beam-induced deposition

An analytical model for the growth of nanopillars by helium ion-beam-induced deposition is presented and compared to experimental data. This model describes the competition between pillar growth in vertical and lateral directions. It assumes that vertical growth is induced by incident primary ions and type-1 secondary electrons, whereas lateral growth is induced by scattered ions and type-2 secondary ions. An essential element of the model is the notion that depletion of adsorbed precursor molecules occurs only at the pillars’ apex. Depletion impedes vertical growth at the apex, allowing more time for lateral outgrowth of the pillar’s sidewalls. The model describes qualitatively the trends in measured vertical, lateral, and volumetric growth rates of PtC pillars as functions of the ion-beam current. It can be used to design growth experiments and Monte Carlo simulations.QN/Quantum NanoscienceApplied Science

Helium-ion-beam-induced growth of 3-dimensional AFM probes

QN/Kavli Nanolab DelftStructural Optimization and Mechanic

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

Nanofabrication with a helium ion microscope

The recently introduced helium ion microscope (HIM) is capable of imaging and fabrication of nanostructures thanks to its sub-nanometer sized ion probe [1,2]. The unique interaction of the helium ions with the sample material provides very localized secondary electron emission, thus providing a valuable signal for high-resolution imaging as well as a mechanism for very precise nanofabrication [3]. The low proximity effects, due to the low yield of backscattered ions and the confinement of the forward scattered ions into a narrow cone, enable patterning of ultra-dense sub-10 nm structures. This paper presents various nanofabrication results obtained with direct-write, with scanning helium ion beam lithography, and with helium ion beam induced deposition.Kavli Institute of NanoscienceApplied Science

Nanofabrication with a High Resolution Helium Ion Beam

Quantum NanoscienceApplied Science