This PhD project focusses on the development of a subsurface nanoimaging technique with the capability of depth sensing and determining the height of a buried object under several layers. The research will be performed based on the already developed subsurface nano-imaging technique so-called Subsurface Ultrasound Resonance Force Microscopy (SSURFM). The current SSURFM enables nondestructive imaging of buried structures with nanometer resolution. However, in the current stage of the development there are two limitations; 1) the results are not quantitative and 2) it is a 2D imaging method without sensitivity to depth. Several applications (e.g. Semiconductor and bio) require quantitative results and information on the depth and height of the buried structures.

SSURFM uses a high-frequency ultrasound wave at a frequency that is typically a few tens of MHz to few GHz—far above the contact resonance. This wave has a sinusoidal amplitude modulation applied at a frequency equal to or close to the cantilever's contact resonance frequency. The cantilever's response is measured at this modulation frequency. At very high frequencies (typically few GHz) where the wavelength is in the same order of magnitude of the size of the buried feature, besides the local elasticity effect there is also wave scattering due to the subsurface features. The cantilever acts as a very sensitive detector, that can detect the scattered wave and map the buried subsurface features.

The primary objective of this research is to further develop the SSURFM with the capabilities of quantitative measurement and having depth sensitivity. Following the modeling part, an experimental demonstration (Proof of principle) will be developed to proof quantitative measurement and depth sensitivity of the newly developed method.

In the project, collaboration with companies will exist, which all offer their expertise to aid the project.

The applicant should have excellent analytical, experimental and communication skills and hold a university degree (MSc) in mechanical engineering, electrical engineering, Physics or similar. A strong interest in dynamics, control, Instrumentation, interactions at small-scales and ultrasound wave and is required. Experience with practical implementation is preferred.

Job co

• A challenging job at a dynamic and ambitious University and in an enthusiastic team.
• An appointment (1 fte) as a PhD-student for four years, starting date: as soon as possible.
• Additional education at PhD level is offered (DISC)
• Gross monthly salaries are in accordance with the Collective Labour Agreement of the Dutch Universities (CAO NU), increasing from € 2325 per month initially, to € 2972 in the fourth year.
• An attractive package of fringe benefits, including excellent work facilities, end of the year allowance, travel to conferences and sport facilities.