Efficient ion-slicing of 4-inch GaAs thin film for Si-based hetero-integration with ultra-smooth surface

Heterogeneous integration of single-crystalline GaAs thin film on a Si substrate provides a promising material platform for Si-based optoelectronic integration. In this work, based on the clarified splitting mechanism of GaAs, the ion implantation conditions for GaAs film transfer were optimized. It was found that the co-implantation of He and H ions is more efficient in exfoliating the GaAs thin film with a lower thermal budget and lower density of defects in comparison with the case of the single He/H ion implantation. With the Al2O3 as the bonding intermediate layer, a 4-inch GaAs film was successfully transferred onto the Si (100) substrate via the optimized ion-slicing technique. The surface treatments, including chemical mechanical polishing, ozone oxidation, and KOH cleaning, were explored to improve the surface quality of the as-transferred GaAs thin film to the level of epi-ready. After post-annealing at 400°C for 1 h, the quality of the transferred GaAs thin film was further improved with only 89.03 arcsec for the full width at half maximum of the X-ray rocking curve.