【Domestic Papers】Low-cost O₂ plasma activation assisted direct bonding of β-Ga₂O₃ and Si substrates in air

      Researchers from the Shandong University have published a dissertation titled "Low-cost O₂ plasma activation assisted direct bonding of β-Ga₂O₃ and Si substrates in air" in Materials Science in Semiconductor Processing.

Abstract

      This study presents a novel technique for directly bonding β-Ga₂O₃ and Si substrates using O₂ plasma activation at room temperature. The activation process resulted in excellent surface hydrophilicity and roughness. Annealing in an N₂ atmosphere revealed a bonding strength of 6.23 MPa, with partial fracture of the Si substrate. The bonding interface was observed by TEM and EDS. A distorted amorphous intermediate layer with a thickness of 100 nm and amorphous bubbles were observed in the bonding interface. In addition, the Ga, O, and Si elements were diffused and enriched, forming approximately 30 nm nodules at the bonding interface. This method offers a promising approach for integrating wide bandgap semiconductor materials in devices, bypassing the need for vacuum treatment.

Original link:https://doi.org/10.1016/j.mssp.2024.108512