Measurement and simulation of interfacial adhesion strength between SiO2 thin film and III–V material

Abstract

Silicon oxide material, which has low-refractive index and high isolation characteristic, has been extensively adopted into high-brightness LED structures. However, the interfacial delamination problem between GaP and SiO2 was observed in the high-brightness AlGalnP LED structure during fabrication process. It indicates that the weak adhesion strength of the GaP/SiO2 interface is a significant issue for manufacturing of LEDs. Therefore, in this study, the interfacial adhesion strength between SiO2 and III–V materials, such as GaP and GaAs, were measured by four-point bend test (4-PBT). In addition, the correspondence of the finite element models with the 4-PBT specimens was also established to predict the interfacial adhesion strength, G value, using the modified virtual crack closure technique (MVCCT) simulation technique. Comparing the predicted G value by MVCCT with experiment results of 4-PBT, the simulation results have good agreement with the experimental data.