In the context of the RARETRANS research project, we are looking for a PhD candidate within the Energy Technology and Flow Dynamics group at the Eindhoven University of Technology (www.energy.tue.nl). The research is on the modelling of heat and mass transport in rarefied gas flows in next generation photo-lithography machines.

Background

Moore's law, which states that computing power doubles every two years, is enabled by perpetual advances in semi-conductor technology. To sustain Moore's law in the coming decades, very fundamental challenges must be confronted. One of these challenges pertains to heat and mass transport in the rarefied gas flows that occur in the exposure region of next-generation Extreme Ultra Violet (EUV) Photo-Lithography Machines (PLM). The power of the EUV light leads to local thermal expansions of the wafer, causing aberrations in the printed nanometer structures, and to discharge of debris in the exposure region. To control the thermal expansion and contain the contamination, small amounts of gas are injected into the exposure region. However, as the exposure process occurs under near-vacuum conditions the resulting gas flow is rarefied. Heat and mass transport in rarefied gas flows are highly complex, and contemporary understanding of these phenomena is very limited.

The aim of the RARETRANS project is to investigate these phenomena and to develop new models and computer-simulation methods to assist developers in designing the next-generation EUV PLM.

Project description

To obtain an accurate representation of gas/solid interactions for the various gas/solid combinations in EUV PLM, we will apply a (sequential) multi-scale approach in which scattering kernels that are extracted from comprehensive Molecular Dynamics (MD) simulations. As opposed to the ad-hoc Lennard-Jones interaction potentials that are the current standard in the literature, we will derive and apply tailored potentials to obtain an accurate representation of the interaction between the multi-atomic gas in EUV PLM and the molecular lattice of the solid substrates.

Based on the stochastic correlations between the approach and recession velocities of gas molecules that collide with the wall, accommodation coefficients will be determined for conventional gas/surface interaction. To validate the scattering kernels obtained from the multiscale approach, the corresponding thermal accommodation coefficients will be compared to experimental data.

The selected candidate will perform numerical simulations and develop novel computer algorithms and computer codes in order to investigate the fundamental physics of rarefied gases. The scientific focus of the project includes the study of the dynamics of small particles under rarefied flow conditions, in presence of thermal effects and realistic flow geometries. The student will employ and further develop Molecular Dynamics codes. He/she will closely interact with ASML, as well as with the other PhD students involved in the project.

We seek highly talented, enthusiastic, and exceptionally motivated candidates with a MSc. degree in mechanical engineering, mathematics, physics or similar. The candidate must be able to demonstrate good programming skills, the drive and capacity to tackle different aspects of a complex problem with large independence, the capabilities to work in a team, strong communication skills, including fluency in written and spoken English.

We offer a full-time appointment for four years, a gross monthly salary from  € 2222,00 (first year) to € 2840,00 (fourth year) in line with the Collective Agreement for Dutch Universities and an attractive package of fringe benefits, including end-of-year allowance, a personal development program for PhD students (Proof program), and excellent sport facilities.