Viscoplastic Buckling of Silicon Ribbon

Silicon ribbon grown by the dendritic web process passes through a rapidly changing thermal profile in the growth direction. This rapidly changing profile induces stresses which cause buckling. Based on a viscoplastic material response function (Haasen-Sumino model), the creep buckling behavior of the silicon ribbon is investigated. The lateral deflection speeds describing the viscoplastic buckling behavior are calculated. It is found that the deflections of some modes increase with time while others die out. The role of the residual stresses in viscoplastic buckling is examined.