NOVELTY - A glass substrate (102) having bonding surface and semiconductor wafer having bonding surface, is prepared. A stiffening layer is formed on one of the bonding surface of the glass substrate and bonding surface of the semiconductor wafer, and ions are implanted to form exfoliation layer (122). The exfoliation layer is bonded on the glass substrate. The exfoliation layer is separated from remaining portion of the semiconductor wafer. The separated surface of the exfoliation layer has surface roughness with skew level of 0.6 or less.    USE - Formation of semiconductor on glass structure (claimed). Uses include but are not limited to thin film transistor, solar cell, organic light emitting diode, liquid crystal display, photovoltaic devices, solar cell, thermoelectric device, sensor, etc.    ADVANTAGE - The method provides semiconductor on glass structure having excellent stiffness and barrier property with respect to sodium and impurities.    DETAILED DESCRIPTION - A glass substrate having bonding surface and semiconductor wafer having bonding surface, is prepared. A stiffening layer having Young's modulus of 125 GPa or more, preferably 300 GPa or more is formed on one of the bonding surface of the glass substrate and bonding surface of the semiconductor wafer. Ions are implanted on the bonding surface of the semiconductor wafer to form exfoliation layer in the bonding surface of the semiconductor wafer. The bonding surface is contacted on the semiconductor wafer with the bonding surface of the glass substrate, with the stiffening layer between the glass substrate and the semiconductor wafer. The exfoliation layer is bonded to the glass substrate, with the stiffening layer between the glass substrate and the semiconductor wafer, by heating the semiconductor wafer and glass substrate to an elevated temperature. The exfoliation layer is separated from remaining portion of the semiconductor wafer, leaving the exfoliation layer bonded to the glass substrate, with the stiffening layer. The separated surface of the exfoliation layer has surface roughness with skew level of 0.6 or less. An INDEPENDENT CLAIM is included for semiconductor on glass structure.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of implanted silicon donor wafer.    Glass substrate (102)    Donor wafer (120)    Exfoliation layer (122)    Weakened zone (123)    Remaining portion of donor wafer (124)