Recent Advances in Heteroepitaxial Growth and Non-Epitaxial Integration of Ga 2 O 3 on Silicon

Gallium oxide (Ga 2 O 3 ) is an emerging semiconductor with a wide bandgap of 4.8-5.3 eV, featuring ultra-high breakdown electric field strength, great thermal stability, and resistance to extreme environments, making it an ideal choice for deep ultraviolet optoelectronic devices, high-power electronic devices, high-frequency Radio Frequency (RF) devices, etc. However, the difficulty in obtaining large-area, high-quality epitaxial layers, together with the intrinsically low thermal conductivity of Ga 2 O 3 , limits its applications. To address these issues, silicon (Si), which possesses good thermal conductivity, as well as the mature and cost-effective semiconductor manufacturing lines, is considered for use as the heteroepitaxial substrate, opening a new path for the low-cost industrialization of Ga 2 O 3 and laying the foundation for next-generation power electronics and specialized optoelectronic devices. This paper reviews the crystal phase characteristics of Ga 2 O 3 , focuses on the lattice and thermal mismatch problems encountered in silicon-based epitaxy, discusses oxide layer removal and buffer layer engineering as conventional heteroepitaxial strategies, and further introduces liquid metal printing as a complementary non-epitaxial integration approach. The current research limitations and future development directions are also discussed.