An air-plasma enhanced low-temperature wafer bonding method using high-concentration water glass adhesive layer

摘要

An air-plasma enhanced low-temperature wafer bonding method using high-concentration water glass adhesive layer has been demonstrated. The high-concentration water glass adhesive layer for wafer bonding has been achieved by introducing nitrogen and preventing CO2, and successfully bonded using spot pressing bonding and air-plasma enhancement for the first time. The tensile strength of the bonded pairs was about 15 MPa and maintained even after long-term storage. The influence of air-plasma treatment was investigated by comparing the contact angles of different substrates and storage time after air-plasma treatment. In addition, the influence of the carbon residue in different preparation conditions were also investigated by X-ray photoelectron spectroscopy (XPS), current-voltage (I-V) and capacitance-frequency (C-f) measurements. The samples coated in nitrogen have lower intensity of carbon, higher leakage current density and lager dielectric constant comparing to the samples coated in the air. Therefore, the bonding method is a promising method for low-temperature bonding with high-concentration adhesive.