1：Experimental Design and Method Selection:

The study involved optimizing the Al2O3-assisted direct wafer bonding process for AlGaAs and sapphire wafers, focusing on intermediate layer deposition and annealing temperature to achieve high bonding strength. High-Q microring resonators were fabricated using electron-beam lithography with a multi-pass exposure process and a thin aluminum layer to mitigate charging effects.

2：Sample Selection and Data Sources:

The samples included AlGaAs and sapphire wafers, with device patterns defined in hydrogen silsesquioxane (HSQ) resist. Data was collected from fabricated microring and racetrack resonators.

3：List of Experimental Equipment and Materials:

Equipment included a JEOL electron-beam lithography system (JBX-9500FS), atomic layer deposition (ALD) for Al2O3 layer deposition, and inductively coupled plasma reactive ion etching (ICP-RIE) for pattern transfer. Materials included AlGaAs and sapphire wafers, HSQ resist, and aluminum for the electrical-field shield layer.

4：Experimental Procedures and Operational Workflow:

The process involved wafer bonding, substrate removal, pattern definition via EBL with a multi-pass process and aluminum layer application, pattern transfer to AlGaAs, and device characterization including linear, nonlinear, and thermal properties.

5：Data Analysis Methods:

The intrinsic quality factor (Qint) was calculated from measured loaded quality factors and transmitted optical power at resonance wavelengths. Nonlinear conversion efficiency and thermal resonance shifts were also analyzed.