Si power devices are quickly approaching their limits due to the intrinsic material properties. Wide bandgap semiconductors with the potential to allow significant performance improvement of power devices became very promising. With numerous studies and successive breakthroughs in recent years, wide bandgap semiconductors in term of material and device fabrication technologies have achieved huge advances. For example, large-size single crystalline substrate, high-quality epitaxial layer on hetero/homo substrate, and various power devices have been commercially available [1]. However, it is still very far to make the best use of the devices’ potential at low cost due to the difficult fabrication process and the expensive substrate. New innovative fabrication technologies are urgently desired. Wafer bonding, as one key technology capable of novel structure formation, efficient fabrication, device integration and cost reduction, is expected to be able to solve many problems in the fabrication of next-generation power device [2].

However, most of the previous wafer bonding of wide bandgap semiconductors need an annealing process at high temperature, even higher than 1000^oC, which would limit its application in device fabrication. A well-developed low temperature wafer bonding method for wide bandgap semiconductors is still absent [3]. In this paper, our recent progress on the wafer bonding of wide bandgap semiconductors at room temperature would be introduced.

References

1. H. Okumura, MRS Bull., Vol. 40, pp. 439-444, 2015.
2. S. H. Christiansen, R. Singh, and U. Gosele, Proc. IEEE, Vol. 94, No. 12, pp. 2060-2106, 2006.
3. F. Mu, K. Iguchi, H. Nakazawa, Y. Takahashi, M. Fujino, R. He, and T. Suga, Appl. Phys. Express, Vol. 9, pp. 081302:1-4, 2016.