Amorphous 2D Materials—A Novel Platform for Remote Epitaxy and Nanopatterned Epitaxy of III-V Semiconductors

III-V semiconductor materials such as indium phosphide (InP) offer outstanding photonic properties that outperform silicon. However, the cost of InP wafers is considerably higher compared to commonly used semiconductor wafers like gallium arsenide (GaAs). While reusing original wafers can effectively reduce costs, traditional techniques for wafer recycling, such as chemical or mechanical lift-off, introduce significant expenses during fabrication, negating the cost savings achieved through wafer reuse. Besides, unlike other III-V materials such as GaAs, the epitaxial lift-off method for wafer recycling has not been extensively investigated for InP due to the lack of lattice-matched sacrificial layers with sufficient etching selectivity. Consequently, the reuse of InP wafers becomes more challenging.<br/><br/>Remote epitaxy and nanopatterned epitaxy have emerged as novel methods capable of facilitating the growth of III-V semiconductor membranes with single-crystal quality, as well as enabling easy exfoliation of these films. These breakthroughs offer a promising avenue for cost-effective wafer reuse. However, traditional approaches for transferring two-dimensional (2D) materials, utilizing polymethyl methacrylate (PMMA) or metal stressor layers to transfer materials grown on foreign substrates like copper (Cu) or silicon carbide (SiC), have been found to introduce defects and damages to both the 2D layer and the substrates during the transfer process. As a result, remote epitaxial and nanopatterned epitaxial films grown on these damaged 2D layers or substrates exhibit lower crystal quality and imperfect exfoliation, hampering wafer reusability and device performance. Additionally, the method of using grown thin amorphous carbon (TAC) for AlGaAs/GaAs is not suitable for InP, since the decomposition temperature of InP (&lt; 600 <b>°C</b>) is significantly lower than the growth temperature of TAC (700 <b>°C</b>).<br/><br/>Here we report the MBE growth of amorphous boron nitride (a-BN) on InP wafers at low temperature that enabled improved quality of remote epitaxial and nanopatterned epitaxial films and their perfect exfoliation. We show fully covered a-BN on InP and InGaAs substrates despite their low decomposition temperatures. The surface of a-BN coated InGaAs/InP substrate remains smooth with RMS roughness of around 3Å. We also demonstrate 100% coverage of single-crystal InP thin films grown on a-BN, with the film’s quality comparable to InP grown directly on wafers. In addition, the growth and exfoliation were successfully repeated multiple times, proving the feasibility for InP wafer recycling. Through this low temperature MBE growth approach with remote epitaxy and nanopatterned epitaxy, we successfully demonstrate large-scale flexible thin film exfoliation and recycling of InP substrates, which will lead to new opportunities in InP thin film-based photonics and novel heterostructures with significantly reduced cost.