QUB- Mechanical and Aerospace Engineering International PhD Project
2015-2016
Title: Modelling and simulation of diamond wire sawing of silicon wafers
Project description:
This project is open to International applicants and is seeking bright candidates to work towards
their PhD at Queen’s University Belfast (UK) in collaboration with a world leader in solar power
systems.
The driver of modern electronic gadgets is Moore’s Law, which says that the count of transistors on
a chip doubles every two years. This drive creates a pressing need for innovative manufacturing
methods to fabricate silicon which has continued to remain a wonder material for electronics.
Historically, Loose abrasive slurry sawing (LSS) has remained the most popular process for
producing PhotoVoltaic (PV) silicon wafers but environmental considerations and high productivity
have pushed the usage of newly emerging technology known as fixed abrasive diamond wire
sawing (DWS) to the forefront.
A typical DWS process, entails sawing large cylindrical ingots of silicon (on a preferred crystal
orientation) using a series of parallel wires. The surface quality of the cut wafers attained by this
method inevitably results in the formation of undesirable micro-fractures and cracks on the silicon
cut surface. Currently there is limited in-depth understanding of the DWS process as the process is
still in its infancy. Therefore, a significant opportunity exists in developing the DWS production
process.
Development of a scientific understanding of the DWS process will improve the yield and reduce
the manufacturing costs, as it can contribute up to 20% of the wafer manufacturing costs. In order
to understand the process, the project will take a simulation based approach involving the use of
Finite Element Analysis (FEA) and Molecular Dynamics Simulation (MDS) using High-Performance
Computing (HPC) facilities. Eventually the aims of this project are to predict:
 the material removal process as a function of the processing equipment and processing
parameters,
 the silicon sub-surface damage mechanisms,
 and the influence of the processing environment.
Accordingly, the following work packages will be executed:
WP1 (1 year): Development of baseline models of the DWS process using FEA and MD on generic
processes and materials.
WP2 (2nd year): The addition of wear and sub-surface damage models and the validation of
integrated modelling approaches.
WP3 (3rd year): Development of predictive optimisation models to assist in cost saving operations
and draw the scientific specifications for the wire performance in line with experimental data.
Key skills required for the post:
Applicants must have a 1st class honours degree in physics/materials science/mechanical
engineering, or any other equivalent qualification. Candidates should be able to demonstrate that
they are highly motivated, have excellent communication skills, and excellent modelling skills: be
able to drive the project by understanding the industrial needs and using their own initiatives. The
project will offer the opportunity for international travel and hence a candidate with mobility is
required.
Key transferable skills that will be developed during the PhD:
The researcher will complete their PhD within a cohort of students researching design and
simulation. The researcher will have access to the experimental suite of the world leading industry
in silicon PV cells, be in continual contact with their R&D engineers and will undergo a secondment
at their site. The researcher will also present their work to project partners at regular technical
meetings and workshops. Recent PhD graduates from this research team have gone on to take up
influential technical positions in leading UK and international engineering companies and so this is
an ideal opportunity to place your career on a leading track.
First/Lead Supervisor and
their contact details
Dr Saurav Goel , Tel: +44 (0)28 9097 5625, Email S.GOEL@qub.ac.uk
Second Supervisor
their contact details:
Dr Adrian Murphy, Tel: +44 (0)28 9097 4095,
and
Funding of the project
Project start date and end
date
The studentship covers the full tuition fees and a tax-free stipend of up to
£18,500 per annum (£17,000 cash/annum and to earn a further £1,500 per
annum by undertaking part time teaching) for a period of three and half
years.
September 2016 to February 2020 (early completion will lead to early
graduation)