Belmont, United Kingdom
Belmont, United Kingdom

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Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2007.3.1 | Award Amount: 2.65M | Year: 2008

Wafer handling in semiconductor manufacturing introduces microcracks at the wafer edge. During thermal processing, some of these grow into slip bands; on rapid thermal processing some of these grow into cracks, shattering the wafer and disrupting manufacture. Dense slip bands also lead to yield loss by locally increasing diffusion rates. Breakage losses alone were of the order of 2.5M p.a. for a single fab line at the 90 nm node. Microcracks and slip bands are visible through X-ray Diffraction Imaging (XRDI); but it is unknown which of the many defects imaged are those that will result in yield loss and breakage. We aim to discover how to derive quantitative, predictive information from XRDI, enabling a breakthrough metrology of wafer inspection. The project will comprise quantification of the XRDI images, modelling of the stresses introduced by the controlled defects, modelling the influence of thermal gradients in RTA upon the defects, and experimental confirmation of the conclusions. The outcome of this research will offer a competitive advantage at several levels to those members of the European Semiconductor Industry who agree to join the Industrial Advisory Board. European wafer manufacturers will have early access to a technique that reveals the nature of the defects in the wafers and their relevance to semiconductor device fabrication. This could provide Europe with a competitive advantage in the development of both 450mm and thin silicon wafers. European wafer and equipment manufacturers will have early access to a unique and specifically developed body of open knowledge to aid them in the evaluation of risk of breakage during their processes. They will have a choice of access to off-line characterization of defects by XRDI at ANKA or an in-line wafer inspection tool commercialized by Bede plc. The knowledge and tools developed will contribute to maintaining Europes leading position in semiconductor x-ray metrology.

Tanner B.K.,Durham University | Wittge J.,Albert Ludwigs University of Freiburg | Vagovic P.,Karlsruhe Institute of Technology | Baumbach T.,Karlsruhe Institute of Technology | And 9 more authors.
Powder Diffraction | Year: 2013

The apparatus for X-ray diffraction imaging (XRDI) of 450-mm wafers, is now placed at the ANKA synchrotron radiation source in Karlsruhe, is described in the context of the drive to inspect wafers for plastic deformation or mechanical damage. It is shown that full wafer maps at high resolution can be expected to take a few hours to record. However, we show from experiments on 200-, 300-, and 450-mm wafers that a perimeter-scan on a 450-mm wafer, to pick up edge damage and edge-originated slip sources, can be achieved in just over 10Â min. Experiments at the Diamond Light Source, on wafers still in their cassettes, suggest that clean-room conditions may not be necessary for such characterization. We conclude that scaling up of the 300-mm format Jordan Valley tools, together with the existing facility at ANKA, provides satisfactory capability for future XRDI analysis of 450-mm wafers. Copyright © International Centre for Diffraction Data 2013.

Tanner B.K.,Durham University | Wittge J.,Albert Ludwigs University of Freiburg | Allen D.,Dublin City University | Fossati M.C.,Durham University | And 5 more authors.
Journal of Applied Crystallography | Year: 2011

High-resolution X-ray diffraction imaging of 200 mm silicon wafers following rapid thermal annealing at a temperature of 1270 K has revealed the presence of many early stage sources of thermal slip associated with the wafer edge. Dislocation sources are primarily at the wafer extremity, though many are generated by damage at the edge of the bevel incline on the wafer surface. A smaller fraction of sources is associated with other regions of localized damage, probably relating to protrusions on the wafer support. The geometry of the latter is similar to that of dislocation sources generated by controlled indentation on the wafer surface. It is concluded that rapid spike annealing at high temperature does not suppress the nucleation of slip, but rather the rapidity of the process prevents the propagation of the dislocations in the slip band into the wafer. © 2011 International Union of Crystallography Printed in Singapore - all rights reserved.

Garagorri J.,University of Navarra | Reyes Elizalde M.,University of Navarra | Fossati M.C.,Durham University | Jacques D.,Jordan Valley Semiconductors UK Ltd | Tanner B.K.,Durham University
Journal of Applied Physics | Year: 2012

X-ray diffraction imaging of 200 mm diameter (100) oriented double-side polished silicon wafers has revealed that the slip band distribution, following rapid thermal annealing (RTA), has a lower symmetry than predicted from the material crystallography. Finite element (FE) modelling of the thermal processes has been undertaken and it is found that, in order to predict the measured temperature distribution during the annealing sequence in a commercial RTA furnace, an anisotropic heat flux distribution in the furnace must be included. When such an anisotropic heat flux is used to predict the wafer temperature, it is found that the temperature gradients are not equivalent in the radial direction. Calculation of the resolved shear stresses on the five independent slip systems associated with these gradients predicts asymmetry between the stress on slip bands that project into the [011] and [01̄1] directions. The anisotropy of the resolved shear stress distribution predicts accurately the asymmetry of the experimentally observed slip band length and density. Rotation of the wafer with respect to the furnace axes results in characteristic and systematic changes in the symmetry of the distribution, which is in good agreement with the finite element predictions. © 2012 American Institute of Physics.

Tanner B.K.,Durham University | Garagorri J.,University of Navarra | Gorostegui-Colinas E.,University of Navarra | Elizalde M.R.,University of Navarra | And 3 more authors.
International Journal of Fracture | Year: 2015

The geometry of fracture associated with the propagation of cracks originating at the edges of (001) oriented, 200 mm diameter silicon wafers has been investigated under two regimes of high temperature processing. Under spike annealing, fracture did not occur on low index planes and all except one wafer exhibited crack patterns that started initially to run radially, but after a distance of typically 20–30 mm, turned and ran almost tangentially. Wafers subjected to plateau annealing, with a 60 s dwell time at high temperature, predominantly fractured through radial cracks running along $$\langle 110\rangle$$⟨110⟩ directions. X-ray diffraction imaging reveals substantial slip in all wafers subjected to plateau annealing. We demonstrate using finite element (FE) modelling that the change in fracture geometry is associated with this plastic deformation, which changes the stress distribution during the cooling phase of the rapid thermal annealing cycle. FE simulations without plastic relaxation show that the radial component of the thermal stress distribution is compressive in the centre of the wafer, causing the crack to run tangentially. Simulations incorporating temperature dependent plasticity showed that the equivalent stress becomes tensile when the plateau anneal allows time for significant plastic relaxation, permitting the crack to continue propagating linearly. © 2015, The Author(s).

Tanner B.K.,Durham University | Fossati M.C.,Durham University | Garagorri J.,University of Navarra | Elizalde M.R.,University of Navarra | And 6 more authors.
Applied Physics Letters | Year: 2012

We show that x-ray diffraction imaging (topography) and finite-element modelling can determine accurately the probability of propagation of individual cracks in brittle single crystal materials. The x-ray image of the crack provides a critical parameter for crack propagation which informs a predictive model, enabling us to identify critical defects that lead to catastrophic shattering of silicon wafers during high temperature thermal processing. Wafers fracture on cooling and finite element modelling shows that, during cooling, the tangential stress at the wafer edge is tensile and results in crack propagation. The predicted fracture geometry agrees extremely well with that observed experimentally. © 2012 American Institute of Physics.

Qi Z.,Dalian University of Technology | Huang H.,Dalian University of Technology | Cao T.,Dalian University of Technology | Liu P.,Dalian University of Technology | And 2 more authors.
Applied Optics | Year: 2013

A fiber pressure sensor with a collimator at the off-center position of a diaphragm is demonstrated. The detection mechanism is incident-angle sensitive rather than traditional working-distance sensitive. Due to the small beam divergence of the collimator, the control on working distance is less stringent, and high sensitivity can be realized because the coupling efficiency of the collimator is very sensitive to the incident angle decided by the off-center diaphragm reflection. Sensitivity of 1.11 and 0.16 dB/KPa can be achieved with silicon diaphragm thicknesses of 100 and 150 μm, respectively. Moreover, the detection range can be continually shifted by changing the pressure in the sealed diaphragm cavity. © 2013 Optical Society of America.

PubMed | Jordan Valley Semiconductors UK Ltd and Dalian University of Technology
Type: | Journal: Scientific reports | Year: 2015

Trace analysis of liquid samples has wide applications in life science and environmental monitor. In this paper, a compact and low-cost photometer based on metal-waveguide-capillary (MWC) was developed for ultra-sensitive absorbance detection. The optical-path can be greatly enhanced and much longer than the physical length of MWC, because the light scattered by the rippled and smooth metal sidewall can be confined inside the capillary regardless of the incident-angle. For the photometer with a 7cm long MWC, the detection limit is improved ~3000 fold compared with that of commercial spectrophotometer with 1cm-cuvette, owing to the novel nonlinear optical-path enhancement as well as fast sample switching, and detecting glucose of a concentration as low as 5.12nM was realized with conventional chromogenic reagent.

Ryan P.,Jordan Valley Semiconductors UK Ltd. | Wall J.,Jordan Valley Semiconductors UK Ltd. | Bytheway R.,Jordan Valley Semiconductors UK Ltd. | Jacques D.,Jordan Valley Semiconductors UK Ltd. | And 2 more authors.
Solid State Technology | Year: 2010

In the future, the production of advanced LED structures is expected to grow more rapidly with the growth in energy efficient, long-lifetime luminaries for general lighting applications. In this article, we will outline the most important measurement capabilities that allow the rapid and reliable control of the LED production process using HRXRD, and the latest advances in HRXRD technology to allow true inline monitoring.

Grant
Agency: GTR | Branch: Innovate UK | Program: | Phase: Smart - Development of Prototype | Award Amount: 159.79K | Year: 2012

The Delta_X project is to develop a X-ray metrology system for the semiconductor industry, capable of measuring and monitoring the key thin films required for low power, high efficiency devices. These devices are being developed to be used in several applications; from solid state LED lighting, solar cells and more efficient high power electronics. All of these require measurement of nanoscale films to improve the performance of the devices and manufacturing efficiency. The films are becoming more complex, meaning existing metrology is not capable of giving the required information in a reasonable timescale for the manufacturer. The new Delta_X system will incorporate new technology on both X-ray sourc and detector to allow the measurement of these advanced films to accelerate the product development and improve the production process of these critical devices enabling the acceleration of higher efficiency lighting and electronics into mainstream use, thus reducing carbon emissions and reducing energy consumption.