Raman Spectroscopy Analysis Of Mechanical Stress Near Cu‐TSVs

This paper discusses Raman spectroscopy measurements of stress near Cu‐TSVs (Through Silicon Vias) used in 3D stacking of thinned chips. It discusses the resolution and penetration depth of the technique and the relation between the measured Raman shift and stress. Using a simple model, the various stress components near TSVs are discussed and the relation between the measured Raman shift and these stress components is analyzed. Results obtained on TSVs with nearby shallow‐trench isolation, with different Cu chemistry, with and without SiO2 layer on top, and with different aspect ratio are discussed and analyzed using the simple model.