Wafer Fused InGaP/GaN Heterostructure

We demonstrated wafer fusion of cubic InGaP and hexagonal GaN. The bonding was carried out at various temperatures ranging from 650°C to 830°C in H₂ atmospheres for 30 ∼ 120 min applying a pressure of about 7 kg/cm². The wafers were successfully bonded above 700°C without using any solders. After wafer fusion, the PL peaks of InGaP and GaAs were blue shifted, which meant that the InGaP and GaAs layers were under compressive strain due to the fusion process. The PL intensity of the InGaP layer degraded slightly as the fusion temperature increased. For a good optical quality, the relative wafer rotational alignment has to be 0°, which is defined as the alignment of the [1-100] direction of GaN and [110] direction of InGaP.