Hydrophilic Bonding of GaN and Diamond Substrates

We have developed a hydrophilic bonding technique for GaN and diamond substrates. Before the bonding step, the GaN substrate was dipped into HCl acid, and the diamond substrate was dipped into NH 4 OH/H 2 O 2 solution to generate hydrophilic surfaces. The treated GaN and diamond substrates were contacted with each other under atmospheric conditions. They are annealed at 300 °C in 2 h for bonding formation. We expect that this bonding technique would contribute to the fabrication of the GaN-on-diamond structure.