For　realizing　the　heterogeneous　integration　of　semiconductor　materials　and　overcoming　the　heat　dissipation　problem　of　GaN-based　high-power　semiconductor　devices,　Mo/Au　interlayers　were　applied　to　realize　the　room　temperature　bonding　between　Si　and　Si,　GaN　and　Si,　GaN　and　diamond,　GaN　HEMTs　and　diamond　wafers　in　atmospheric　air.　Low　voidage　and　high　bonding　strength　were　achieved.　In　addition,　the　temperature　distributions　and　thermal　resistances　of　the　devices　bonded　on　different　substrates　(sapphire,　Si,　SiC　and　diamond)　with　Mo/Au　interlayers　were　calculated　by　numerical　simulation.　©　2021　IEEE