Thermally Conductive Buried Aluminum Nitride for Next Generation Silicon‐on‐Insulator

Abstract Silicon‐on‐insulator (SOI) substrates suffer from heat‐confinement and self‐heating effects due to silicon dioxide's low thermal conductivity. Polycrystalline Aluminum nitride (AlN) films can be a good replacement for effective heat dissipation while being an excellent electrical insulator. This study reports AlN films grown using reactive magnetron sputtering, atomic layer deposition (ALD), and metalorganic vapour phase epitaxy (MOVPE) on Si (111) substrates. The strongly oriented MOVPE film has a thermal conductivity of 191 W m −1 K −1 and thermal boundary conductance (TBC) of 147 MW m −2 K −1 . Modified Williamson‐Hall (W‐H) plot can provide grain size analysis for these highly oriented films to monitor the expected thermal conductivity. This study shows the feasibility of reactively sputtered and MOVPE AlN films as an integrated cross‐plane heat spreader in our AlN‐SOI platform.