A hybrid experimental/numerical approach to characterize interfacial adhesion in multilayer low-kappa thin film specimens

作者：Kitey Rajesh; Sottos Nancy R^*; Geubelle Philippe H

来源：Thin Solid Films, 2010, 519(1): 337-344.

DOI：10.1016/j.tsf.2010.07.094

• Dynamic wave propagation
• Laser spallation
• Low-kappa
• Thin film
• Decompression shock

The strength of multilayer low dielectric (low-kappa) constant organo-silicate glass (OSG) and silicon-carbon-nitride (SiCN) thin film interfaces is characterized by a laser spallation technique. Two specimen sets with different OSG/SiCN stacking sequences are evaluated. The effect of helium (He) pretreatment is also investigated. The stress at the low-kappa interface is enhanced through the use of a fused silica backing layer to shape the incident pulse and the addition of a thin gold (Au) top layer to increase inertial force during the dynamic failure event. The weakest interface in the multilayer stack (first to fail) is identified through optical images, profilometry and scanning electron microscope images of the spallation zone. The strength of the failed interface is inferred from the incident stress history in combination with a one dimensional dynamic wave propagation analysis. The adhesion strength of the OSG/SiCN interface (372 MPa) is 32% larger than that of Si/OSG (282 MPa) for specimens with no He pretreatement. The interfacial strength of both interfaces is significantly increased by a He pretreatment, making failure by spallation difficult.

• 出版日期2010-10-29