Direct Electrodeposition of InSb Devices on Silicon
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 (GaN) for power electronics and III-Vs (InSb, InGaAs, AlSb, etc.) 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. This work addresses this challenge demonstrating 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 deposition conditions with particular attention to stability and reproducibility of the process as well as an evaluation of the best electrode configuration. Building on 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.