Method of forming silicon on insulator substrate

A method of forming an SOI substrate, themethod comprising:

• sequentially stacking an etch stopper layer containing SiGe, a semiconductor layer containing Si, a buried insulation layer and a first bonding insulation layer on an upper surface of a donor wafer to form a donor wafer structure;
• forming a second bonding insulation layer on an upper surface of a carrier wafer to form a carrier wafer structure;
• bonding the donor wafer structure with the carrier wafer structure to form a bonding structure in which a back surface of the donor wafer faces upwardly;
• grinding the back surface of the donor wafer;
• cleaning a grinded surface of the bonding structure;
• stripping the donor wafer remaining after the grinding by a spin cleaning process to expose the etch stopper layer;
• removing the exposed etch stopper layer, in a plasma process chamber in which a recombination aid layer is coated, using a plasma cleaning gas including NF3 to expose the semiconductor layer;
• and
• treating a surface of the semiconductor layer to have a uniform thickn13ess.