Mask absorbers for EUV lithography require specific materials with specific optical properties (n,k) at l=13.6nm. The absorber film is part of the EUV image formation mechanism and is placed on top of the EUV mirror, which top layer is composed of Ru. Currently, multiple materials and alloys are considered as absorber candidates, amongst which RuTa binary alloy. This metal alloy need to be patterned selective to pure Ru. The topic of the internship will be devoted to the study of selective etching of RuTa over Ru, by optimization of plasma parameters using state-of-the art plasma chambers and techniques. The change of plasma etch rate will be studied for varying alloying Ta percentage.
The goal of the process is to remove the whole RuTa with minimal damage to the Ru (sub-nanometer removal). Screening of plasma chemistries (Cl2/O2, BCl3/O2 ratio, potential additives), plasma physical parameters (pressure, power, bias) and sequences (plasma cycles) will be investigated; the etch and selectivity mechanisms will be studied using ellipsometry, AFM, XRR, SEM and XPS.
At arrival in MEC, the intern will follow mandatory training on 1) general safety, 2)cleanroom behaviour, 2) safety in cleanroom, 3) safely tidying up chemicals, 4) chemical lab, 5) working in FAB, 6) wetbench and chemicals. In order to speed up learning and maximize the experimental output of his stay, the student will start work as soon as possible together with a mentor. The candidate will be trained at IMEC, on the following techniques: ellipsometry and/or XRR, plasma etching, AFM. The intern will interact with analysts specialized in specific surface characterization techniques such as XPS, AFM and will be trained on the interpretation of generated data. The intern will be coached, at IMEC, by Dr Jean-François de Marneffe (STS/UPM/NCAIS group directed by Stefan De Gendt) and Dr Laurent Souriau (STS/UPM/ETCH/BEOL team directed by Dr Frederic Lazzarino). The intern will report his work in internal meeting (ETCH-BEOL and advanced litho).
Type of project: Combination of internship and thesis
Duration: 4-9 months
Required degree: Master of Engineering Technology, Master of Science, Master of Engineering Science
Required background: Chemistry/Chemical Engineering, Materials Engineering, Nanoscience & Nanotechnology, Physics
Supervising scientist(s): For further information or for application, please contact: Jean-Francois de Marneffe (Jean-Francois.deMarneffe@imec.be)
Imec allowance will be provided for students studying at a non-Belgian university.