This EArly-concept Grant for Exploratory Research (EAGER) grant provides funding for testing the feasibility of pulsed laser processing that would enable high rate and cost effective exfoliation of thin single crystalline silicon carbide (SiC) layers suitable for fabrication of micro-devices. The attractiveness of single crystalline SiC in a variety of device applications is counteracted by the very high cost of substrates. The main goal of this project is to exfoliate multiple thin layers from one standard thickness SiC wafer using hydrogen ion implantation and laser processing, and transferring such layers to silicon or polycrystalline SiC substrates in order to enable a broader use of this material. Hydrogen ion implantation into SiC can form a zone of voids and microcracks at a depth approximating the implantation range, and lead to exfoliation at subsequent very high temperatures. The proposed approach of laser-assisted exfoliation would utilize a lower implantation dose and lower annealing temperatures, thus reducing damage and allowing bonding of SiC to temperature-sensitive substrates. Interactions between ion implantation conditions, laser irradiation, and heating will be explored to gain preliminary understanding of the path leading to exfoliation of continuous single crystalline layers suitable for electronic devices. Feasibility studies of the proposed process will be conducted and structural and electrical properties of processed samples will be investigated. This research will concentrate on a 4H polytype of SiC, as it is of most relevance for power and high voltage applications, but laser-assisted exfoliation should also be extendable to other semiconductors and wide bandgap materials, such as gallium nitride (GaN). If successful, the results of this exploratory research will lead to development of a rapid and cost-effective method of exfoliating single crystalline layers of SiC and bonding them to lower cost substrates that are compatible with high performance electronic, photonic, sensor, or MEMS device operation.
|Effective start/end date||9/1/11 → 8/31/12|
- National Science Foundation (NSF)