The transfer of thin layers (2D materials, III/V, topological insulators...) is a very appealing technology as it has the promise to integrate new materials in CMOS manufacturing that are otherwise difficult to access due to incompatible substrates (e.g., sapphire, GaAs...), high temperature processing or even the need for a metal catalyst (e.g., graphene on Cu).
To enable thin layer transfers, it is essential to find pathways to overcome adhesion between the deposited material and the substrate, without negatively impacting the layer. This might be possible by using sacrificial layers (e.g., laser or epitaxial lift-off layers), intercalation effects, strain engineering... The next challenge is to control the interaction between the transferred layer and the target/device wafer to achieve the desired properties of the transferred layer (high mobility, specific bandgap...). Therefor, it will be critical to precisely control the surroundings of the transferred layer to achieve a uniform bond interface which should enable a controlled doping and strain level in the material.
MX2 materials are currently considered as the channel material for next generation transistor devices. A possible integration route includes the transfer of the 2D material from its growth substrate (i.e., sapphire) to a device wafer. It is of prime importance to determine the defectivity level in this 2D material before, during and after the transfer process and to tune its interface properties to maintain or even enable high mobility 2D layers. Low-temperature photoluminescence (LT-PL) could be a valuable tool to monitor and optimize the transfer procedure, as it has the promise to assess not only defectivity, but also strain, doping and its dielectric environment.
What you will do
The transfer of WS2 and MoS2 is implemented at Imec with a glass carrier wafer, a laser release layer, and a polymer support. A critical bottleneck remains the defectivity assessment during the different steps of the transfer procedure (i.e., delamination, bonding, carrier removal and cleaning steps). LT-PL (possibly with time-resolved capabilities) might be a good metrology for defectivity analysis of MX2 layers. The measured defectivity values will depend on the surroundings of the 2D material, and fundamental understanding is needed to enable the use of this technique for 2D material transfer quality assessment. It will be critical to evaluate PL as a defectivity technique and validate the obtained results with other characterization techniques.
What we do for you
We offer you the opportunity to join one of the world’s premier research centers in nanotechnology at its headquarters in Leuven, Belgium. With your talent, passion and expertise, you’ll become part of a team that makes the impossible possible. Together, we shape the technology that will determine the society of tomorrow.
We are committed to being an inclusive employer (http://www.imec-int.com/en/careers#diversity) and proud of our open, multicultural, and informal working environment with ample possibilities to take initiative and show responsibility. We commit to supporting and guiding you in this process; not only with words but also with tangible actions. Through imec.academy, 'our corporate university', we actively invest in your development to further your technical and personal growth.
We are aware that your valuable contribution makes imec a top player in its field.
Who you are
To enable and to increase our fundamental understanding of the transfer process, we are looking for a postdoc with a deep knowledge of characterization techniques and a proven track record with thin film transfer.
You will be a member of the Bonding, Transfer and Assembly (BTA) group, but you will also work in close collaboration with the Materials, and Components Analysis (MCA) group to assess defectivity in 2D materials and the Lab team to assess transfer methodologies that are scalable.
This postdoctoral position is funded by imec through KU Leuven. Because of the specific financing statute which targets international mobility for postdocs, only candidates who did not stay or work/study in Belgium for more than 24 months in the past 3 years can be considered for the position (short stays such as holiday, participation in conferences, etc. are not taken into account).Continue reading
|Title||Postdoctoral Researcher Scalable transfer of extremely thin layers|
|Job location||Kapeldreef 75, B-3001 Heverlee|
|Published||September 3, 2021|
|Job types||Postdoc  |
|Fields||Materials Engineering,   Materials Chemistry,   Catalysis,   Polymer Chemistry,   Surface Chemistry,   Materials Physics,   Laser Physics  |