Viscoelastic Stress Relief in Patterned Silicon-on-Insulator Structures

Abstract

AbstractA high-temperature viscoelastic stress relief technique has been investigated as a means for reducing in-plane stress encountered during zone-melt recrystallization of patterned silicon-on-insulator structures. This technique incorporates a phosphosilicate glass layer between the silicon film and the insulating substrate to provide a viscous flow mechanism for stress relief within the composite structure. The stress relaxation can bequalitatively described by a mechanical model which couples thermal expansion and viscoelastic flow. The model predicts the time constant for stress relief at high temperatures as a function of pattern size, and the results are useful as a design aid for zone-melt recrystallization experiments.