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

TL;DR

This study compares different electrode structures for measuring the dielectric breakdown of hexagonal boron nitride, highlighting environmental factors affecting measurement consistency and providing guidelines for accurate evaluation of h-BN quality.

Contribution

It systematically investigates how electrode structure and environmental conditions influence dielectric breakdown measurements of h-BN, establishing best practices for accurate assessment.

Findings

EBD is insensitive to contact force and electrode area.

Relative humidity significantly affects EBD measurements.

Proper environmental control yields consistent EBD values across electrode structures.

Abstract

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 (EBD) is one of the most important methods to elucidate the insulating quality of h-BN. In this work, the EBD 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 EBD measurement. A systematic investigation revealed that EBD 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 EBD 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.