A novel strategy for GaN-on-diamond device with a high thermal boundary conductance

To achieve high device performance and reliability for the gallium nitride (GaN)-based electron mobility transistors (HEMTs), efficient heat dissipation is important but remains challenging. Enormous efforts have been made to transfer a GaN layer onto diamond substrate with thermal conductivity by bonding. In this work, two GaN-diamond bonded composites are prepared via modified surface activated bonding (SAB) at room temperature silicon interlayers of different thicknesses (15 nm 22 nm). Before after post annealing process 800 °C, boundary conductance (TBC) across interface including interlayer stress investigated time-domain thermoreflectance Raman spectroscopy, respectively. case as-bonded samples, TBC 15 Si (32.4 MW/m2-K) was higher than that (28.0 MW/m2-K); annealing, (71.3 became lower (85.9 MW/m2-K), because especially effective thicker improved interfacial TBC. The obtained less 230 MPa both before stability indicates room-temperature can realize GaN-on-diamond template suitable further epitaxial growth or process.