| 摘要 |
PURPOSE:To generate effective gettering by preventing the formation of a defect in the extremely surface layer of a semiconductor substrate as the active region of an element while generating an extremely large number of defects in the substrate. CONSTITUTION:When the surface layer of the semiconductor substrate grown through a czochralski method is heated at 350 deg.C and the whole surface of the substrate is scanned by CW laser beams, the region 22 of the shallw surface layer 0.5-0.6mum of the substrate is elevated to a temperature such as approximately 1,400 deg.C, the all defect unclei of the region are extinguished, and the concentration of oxygen is suddenly decreased. No defect is formed in the region 22 and the defects of extremely high density are generated in a deep region 23 because dissolved oxygen is precipitated in the deep section 23 of the substrate and the nuclei of the defects are shaped through heat treatment for sixteen hours at the low temperature of 650-800 deg.C and the defects 24 are formed to the deep section 23 of the substrate through heat treatment for six hours at the high temperature of 900-1,100 deg.C. The element such as a MOS type element is formed to the surface layer 22. |
