Two‐Inch Wafer‐Scale Exfoliation of Hexagonal Boron Nitride Films Fabricated by RF‐Sputtering

Abstract

A film stripping method that allows for liquid phase exfoliation assisted by spin coating polymethyl methacrylate has been investigated, resulting in a two‐inch hexagonal boron nitride (hBN) film to be fully stripped and then transferred. A number of key factors that can influence the stripping and the transferring process of the films grown by sputtering have been systematically analyzed, including different solutions, different concentration of solution and different thickness of films. The morphology and properties of the hBN films before and after stripping have been characterized. The band edge absorption peak of the transferred film is 229 nm and the corresponding optical band gap is 5.50 eV. Such transferred hBN films have been fabricated into transparent resistive switching devices on indium‐tin‐oxide glass, demonstrating a constant resistance window of ≈102 even under different applied voltages. This work systematically studies the stripping process, characterizes the transferred films, and explores the application in the field of resistance switching, which lay a foundation for the further application of hBN materials in optoelectronic devices.

Electronic Properties of Vertically Stacked h-BN/B1–xAlxN Heterojunction on Si(100)

“…Furthermore, the h-BN/B 1– x Al x N heterojunction with a centimeter scale area was first constructed based on the mature stripping technology of 2 in. wafer-scale h-BN in our previous study . The obvious rectification properties suggested that the low formation energy of heterojuncion existed in h-BN/B 0.89 Al 0.11 N heterojunction.…”

“…wafer-scale h-BN in our previous study. 27 The obvious rectification properties suggested that the low formation energy of heterojuncion existed in h-BN/B 0.89 Al 0.11 N heterojunction.…”

“…27 Al 0.73 N film sample of 175 W with wurtzite structure was proposed. The serious lattice mismatch directly leads to the disappearance of the rectification characteristics.…”

“…The lattice-matched h-BN/B 0.89 Al 0.11 N heterojunction also presents a lower formation energy of heterostructure, which proves a way to construct the heterojunction by exfoliation and transfer method. The wafer-scale h-BN film could be peeled off based on our previous liquid phase exfoliation technology 27. Then, the stripped h-BN film was superimposed on B 0.89 Al 0.11 N/Si template to construct the h-BN/B 0.89 Al 0.11 N/Si structure.The baking process was used to improve the interface contact quality with 200 °C, 300 °C, and 400 °C heating for 3 h in a nitrogen/argon atmosphere.…”

Synthesis of Two-Dimensional Hexagonal Boron Nitride and Mid-Infrared Nanophotonics

“…Recently, Li et al 155 further realized the wafer-level continuous exfoliation of h-BN on the basis of the previous magnetron sputtering preparation of h-BN films and obtained the wafer-level transfer of h-BN films. Factors affecting the exfoliation and transfer of continuous thick films grown by sputtering were analyzed, including different exfoliation solutions (acid/base/deionized water), different solution concentrations (0.1−6 mol/L), and different film thicknesses (50−120 nm).…”