Water-based, large-scale transfer of 2D materials grown on sapphire substrates

Two-dimensional materials (2DMs) hold significant potential for future electronics, as demonstrated by high-performing devices for sensing, optics, and electronics. However, scalable growth techniques such as metal-organic chemical vapor deposition (MOCVD) typically require high temperatures, which limit their integration with conventional semiconductor processes. Therefore, reliable transfer processes from crystalline, low-contamination growth substrates such as sapphire are essential. Existing methods using chemicals such as potassium hydroxide (KOH) have potential quality issues and require manual handling and enhanced safety precautions. Here, we introduce a deionized water-based, frame-assisted, large-scale transfer method for two widely used two-dimensional materials, molybdenum disulfide (MoS ₂ ) and hexagonal boron nitride (h-BN). We demonstrate the scalability of our process with the transfer of MoS ₂ from a 100 mm diameter sapphire wafer. The material quality was verified as-grown and after transfer via atomic force microscopy, scanning electron microscopy, and Raman spectroscopy. The data show less compressive strain levels and insignificant changes in the doping or contamination of 2DMs after transfer.