Van Der Waals Integration of 4-Inch Single-Crystalline III-Nitride Semiconductors

Heteroepitaxy III-nitride semiconductors on 2D materials, characterized by a van der Waals (vdW) interface, enables strain relaxation, reduction in dislocation density, and facile release from substrate. However, the limited wettability of 2D materials and weak interfacial interactions pose significant challenges in achieving ordered crystallographic orientation of III-nitride semiconductors at the wafer scale. Here, this study has been successfully developed a polarization-engineered vdW integration strategy (PEVIS) for the growth of wafer-scale single-crystalline III-nitride semiconductors. By engineering robust electronic polarization in epitaxial substrates, the growth of 4-inch single-crystalline GaN layers is successfully achieved on wafers coated with 2D materials using PEVIS. Additionally, this approach exhibits a remarkably low threading dislocations density of 3.49 × 10⁸ cm^-2 on the vdW surface, even when the GaN epitaxial layer thickness is reduced to 400 nm. Furthermore, the fabricated GaN high electron mobility transistors (HEMTs) achieve an average high mobility of 2080.7 cm² V^-1 s^-1, a high saturation current density of 790 mA mm^-1, and effectively mitigates the off-state leakage current to 1.11 × 10^-6 mA mm^-1. This work signifies a significant advancement in the theoretical comprehension of heteroepitaxy on 2D materials and introduces a novel methodology for fabricating wafer-scale single-crystalline high-quality III-nitride semiconductors.