Fracture Dynamics during the Silicon Layer Transfer of the Smart Cut™ Process

Abstract

Fracture crack propagation involved in silicon layer transfer of the Smart Cut™ process is experimentally studied. Measurements of both crack propagation velocity and crack opening displacement are performed at different temperatures using a specially designed optical setup. After a quick acceleration, the fracture velocity is found to be constant along the sample, with values in the km.s-1 range. The crack deformation profile is shown to be oscillatory, with typical wavelength in the centimeter range. The increase of temperature leads to higher crack velocities and gap openings due to an increase of the gas pressure inside microcracks. The maximum air gap thickness increases linearly with the splitting temperature, as expected for an ideal gas expansion.