Comparison of device structures for the dielectric breakdown measurement of hexagonal boron nitride

摘要

Improving the film quality in the synthesis of large-area hexagonal boron nitride films (h-BN) for two-dimensional material devices remains a great challenge. The measurement of electrical breakdown dielectric strength (E_(BD)) is one of the most important methods to elucidate the insulating quality of h-BN. In this work, the E_(BD) of high quality exfoliated single-crystal h-BN was investigated using three different electrode structures under different environmental conditions to determine the ideal electrode structure and environment for E_(BD) measurement. A systematic investigation revealed that E_(BD) is not sensitive to contact force or electrode area but strongly depends on the relative humidity during measurement. Once the measurement environment is properly managed, it was found that the E_(BD) values are consistent within experimental error regardless of the electrode structure, which enables the evaluation of the crystallinity of synthesized h-BN at the microscopic and macroscopic level by utilizing the three different electrode structures properly for different purposes.