TECNO

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska–Curie grant agreement No 894326.

The principal investigator is Katarzyna Hnida-Gut, and the host institution is IBM Research GmbH, which is an industrial research laboratory located in Rüschlikon, Switzerland.

TECNO started in November 2020 and was completed in July 2022.

Electronic devices based on inexpensive Si technology by far dominate the market for data processing, imaging as well as sensing devices today and in the foreseeable future. Nevertheless, non-Si semiconductors are gaining significant momentum in specialized fields where it is motivated by performance metrics considerably surpassing that of Si. These include wide bandgap semiconductors for power electronics and III-Vs for sensing and high-speed electronics. Therefore, a large economic potential could result if these two material platforms could seamlessly merge. However, technological difficulties challenge the integration of foreign materials directly on Si due to the crystal lattice, thermal and polarity mismatch leading to the large density of defects, detrimental to most applications. In addition, the implementation of such a heterogeneous platform must be cost competitive over current approaches. Another equally grand challenge is to provide a platform for emerging sensing and quantum computing technologies where even more exotic material sets are envisioned.

The TECNO project addresses these two challenges in material science and device integration by exemplifying a solution to an exciting but acknowledged difficult problem: Indium antimonide (InSb) on silicon. One of the milestones of the project was to demonstrate the direct electrodeposition of indium antimonide on Si in defined geometries by an up-scalable and environmentally friendly aqueous solution process. We have evaluated several electrochemical depositions with particular attention to stability and reproducibility of the process as well as an evaluation of the best electrode configuration [1]. Building of these results, we show that prefabricated hollow template structures of micro- and sub-micron dimensions, each containing a local embedded electrode can be successfully filled with electrodeposited InSb resulting in well-defined device structures on Si. This combines the advantages of high-speed low-cost electrodeposition with the increased control achievable using templates.

Another milestone in the project was to successfully recrystallize InSb deposit inside the template. Due to the characteristics of the InSb electrodeposition, the obtained material is polycrystalline which significantly limits its practical use. To overcome this, concepts borrowed from micro zone recrystallization and rapid melt growth were applied. Here, the samples were subjected to a short high temperature step exceeding the melting temperature. During this step the polycrystalline sample melts and recrystallizes from a seed interface resulting in a single crystalline structure with epitaxial relationship to the substrate.