Electrical insulation characteristics of metal-insulator-metal structures using boron nitride dielectric films deposited with low-energy ion impact

Abstract

Sp2-bonded boron nitride (BN) films are deposited on Ni and Si substrates with mean ion impact energies between a few eV and around 100 eV by surface-wave plasma enhanced chemical vapor deposition and their electrical insulation characteristics are examined for temperatures up to 300 °C. The overall crystallinity and order of sp2 structure in the films increase with decreasing ion energy, while the mass density becomes as high as sintered hexagonal BN only when the ion energy is above ∼50 eV. For a given temperature, the electrical resistivity of the films measured for metal-BN-metal structures increases with decreasing ion energy, and hence increasing crystallinity and order of sp2 structure, almost independent of mass density. A decrease in resistivity with temperature is small below 150 °C, then becomes large above 150 °C with a drastic increase in apparent activation energy for carriers, which is attributed to generation and transport of the carriers that get over higher barrier heights associated with stronger ion impact.