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Durham University

Institute of Medieval and Early Modern Studies (IMEMS)

Staff and Governance

Core Staff

The day-to-day running of IMEMS is the responsibility of the Core Executive Committee, comprising the Director and Associate Directors and the Administrator. 

Publication details for Prof Brian Tanner

Tanner, B. K., Garagorri, J., Gorostegui-Colinas, E., Elizalde, M. R., Bytheway, R., McNally, P. J. & Danilewsky, A. N. (2015). The Geometry of Catastrophic Fracture during High Temperature Processing of Silicon. International Journal of Fracture 195(1-2): 79-85.

Author(s) from Durham

Abstract

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 ⟨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.


Full Executive Committee

Our Full Executive Committee is made up of the Core Executive Committee, listed above, plus a number of executive members including:


International Advisory Board

We are extremely fortunate to have be able to call on the help and guidance of colleagues from around the world who help to shape and guide our direction, strategy and international reach. Our current Advisory Board members are: