/Study of area-selective deposition in nanometer devices using RBS

Study of area-selective deposition in nanometer devices using RBS

Research & development - Leuven | More than two weeks ago

Metrology enabling technology

To keep up with Moore’s law, the semiconductor industry continues to push the envelope in developing smaller and better-performing devices. Advanced EUV lithography and area-selective deposition (ASD) gain interest because they allow to produce devices with nanometer dimensions. Besides, new materials are being introduced such as ruthenium as a future interconnect or hard mask material and germanium antimony tellurium (GST) as a future phase change memory material. A critical issue for the acceptance of ASD for this application is the availability of an adequate metrology which is capable of probing the reduced dimensions of the devices. Rutherford backscattering spectrometry (RBS) provides unique quantitative analysis capabilities for such applications tough it is normally not associated with the analysis of very fine features.


Our team has recently demonstrated for the model case of Ru ASD on a TiN base layer in trenches between SiO2 fins of 30 nm width, that a judicious choice of analysis conditions combined with advanced data treatment can overcome the spatial limitations usually associated with RBS. Furthermore, we have demonstrated that RBS provides a unique step forward in quantitatively characterizing area-selective deposition on nanostructures with high sensitivity and virtually no restrictions on device dimensions. Our ongoing research is aiming at reaching a true 3D tomographic RBS analysis for such devices.


The master thesis/internship project will aim at applying and extending the new RBS technique to unravel previously unmeasurable details of the early-stage ASD process in nanostructures. In an initial phase the student will investigate the Ru ASD process using the new RBS technique for different deposition methods (CVD or ALD), as well as different surface chemical parameters. In a later stage, depending on the interest of the student, one of two extensions of the technique may be explored: the study of ASD of compounds such as GST in nanostructures, or the study of the sidewall deposition pattern. Conventionally characterized sets of samples are already available. The project is well suited for a student envisioning an academic research career (PhD), as well as a career in the R&D industry.

Type of project: Combination of internship and thesis

Duration: 6 - 12 months

Required degree: Master of Science, Master of Engineering Science

Required background: Physics, Nanoscience & Nanotechnology

Supervising scientist(s): For further information or for application, please contact: Niels Claessens (Niels.Claessens@imec.be) and Johan Meersschaut (Johan.Meersschaut@imec.be)

Imec allowance will be provided for students studying at a non-Belgian university.