Thermal conductivity evaluation of GaN-AlN-(4H)SiC hetero-epitaxial material system

► Effective thermal conductivity of GaN-AlN-(4H)SiC material system is evaluated. ► Callaway approach is made to know the thermal conductivities of the materials. ► Effective thermal conductivity of GaN-AlN-(4H)SiC is≅2.0 W/cm Kwithout (4H)SiC. ► Effective thermal conductivity of GaN-AlN-(4H)SiC is≅4.0 W/cm K with (4H)SiC. ► GaN-AlN-(4H)SiC is favorable for high frequency and high temperature operation.