Patent ID: 8058148

Claim:
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 X- and Y- axial directions, and the height defining a longitudinal axis; and subjecting the donor semiconductor wafer to a spatial variation step during 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 the X- and Y- axial directions, wherein the ion implantation step includes: (i) implanting a first species of ions in a substantially uniform manner to create a weakened slice of substantially uniform distribution; and (ii) implanting a second species of ions in a substantially non-uniform manner, such that the second species of ions causes migration of atoms to the weakened slice resulting in the spatially varying densities of nucleation sites across the weakened slice.