Patent ID: 7816225
Filing Date: 2010-10-19
Classification: H01L

Abstract:
1. A method of forming a semiconductor-on-insulator (SOI) structure, comprising: subjecting an implantation surface of a donor semiconductor wafer to an ion implantation step to create a weakened slice in cross-section defining an exfoliation layer of the donor semiconductor wafer, where the donor semiconductor wafer has a width, a depth and a height, the width and depth defining the X-and Y-axial directions, and the height defining a longitudinal axis; and tilting the donor semiconductor wafer such that the longitudinal axis thereof is at a non-zero angle Φ with respect to a directional axis of an ion implantation beam and subjecting the donor semiconductor wafer to a spatial variation step, either before, during or after the ion implantation step, such that densities of nucleation sites resulting from the ion implantation step vary spatially across the weakened slice in at least one of X-and Y-axial directions.