摘要 |
An SOI substrate having a single crystal semiconductor layer with high surface planarity is manufactured. A semiconductor substrate is doped with hydrogen, whereby a damaged region which contains large quantity of hydrogen is formed. After a single crystal semiconductor substrate and a supporting substrate are bonded together, the semiconductor substrate is heated, whereby the single crystal semiconductor substrate is separated in the damaged region. While a heated high-purity nitrogen gas is sprayed on a separation plane of the single crystal semiconductor layer separated from the single crystal semiconductor substrate, laser beam irradiation is performed. By irradiation with a laser beam, the single crystal semiconductor layer is melted, whereby planarity of the surface of the single crystal semiconductor layer is improved and re-single-crystallization is performed.
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