Increasingly complex 3D shapes are used as Semicon devices, requiring advanced metrology techniques to monitor production and understand performance of the devices. Atomic force microscopy allows to reach the required sub-nm accuracy by using relatively blunt probes, sensing always in the same direction, but only the top of the 3D shapes can be explored. This project aims to enable the use of nanotube-based probes to scan the profile on the samples with more challenging topographies. The nanotube probe shape strongly improves how well holes or trenches in the sample can be accessed. However, the slender probes become weaker in lateral direction, while sensitivity in this direction is also needed to thoroughly scan the samples.

This PhD Position aims to understand the nonlinear dynamics that drive the probe motion in the neighbourhood of high-aspect ratio sample structures. In particular, van der Waals-type attractive forces, electrostatic forces and squeeze-film damping forces will bring a strongly nonlinear force-position dependency, which, in contrast to conventional approaches, cannot be understood by a spherical tip & flat surface approximation. Hence, a 3D force model of the probe tip in the vicinity of the sample will be developed.

Based on the dynamical analysis derived from this force model, a two-dimensional sensing capacity will be developed where profile information can be obtained in longitudinal as well   as in lateral direction of the nanotube probe. Hence, sideways bending and buckling of the narrow probe will be also be considered. Experimental validation of the 2D profile sensing is foreseen. The PhD Candidate will be partially located at TNO Optomechatronics, Delft and partially at the TU/e Dynamics and Control group.

• A master's degree (or an equivalent university degree) in Mechanical Engineering, Electrical Engineering, Mechatronics, Physics, or any related field.
• A research oriented attitude.
• Ability to work in a team and <interested in collaborating with the industrial partners>Fluent in spoken and written English.

• A meaningful job in a dynamic and ambitious university with the possibility to present your work at international conferences.
• A full-time employment for four years, with an intermediate evaluation (go/no-go) after nine months.
• To develop your teaching skills, you will spend 10% of your employment on teaching tasks.
• To support you during your PhD and to prepare you for the rest of your career, you will make a Training and Supervision plan and you will have free access to a personal development program for PhD students (PROOF program).
• A gross monthly salary and benefits (such as a pension scheme, pregnancy and maternity leave, partially paid parental leave) in accordance with the Collective Labor Agreement for Dutch Universities.
• Additionally, an annual holiday allowance of 8% of the yearly salary, plus a year-end allowance of 8.3% of the annual salary.
• Should you come from abroad and comply with certain conditions, you can make use of the so-called '30% facility', which permits you not to pay tax on 30% of your salary.
• A broad package of fringe benefits, including an excellent technical infrastructure, moving expenses, and savings schemes.
• Family-friendly initiatives are in place, such as an international spouse program, and excellent on-campus children day care and sports facilities.