| 摘要 |
PURPOSE:To reduce the occurrence of infinitesimal fault in a silicon monocrystalline wafer at heat treating time by cutting to form the wafer with a silicon monocrystalline ingot, etching to remove cut strain of one surface to become front surface of the cut strains on the surface layer and retaining the strain on the other back surface thereof. CONSTITUTION:A silicon wafer cut from a silicon monocrystalline ingot formed by a pulling method produces an infinitesimal fault from the surface to the interior due to the presence of cut strain at the heat treatment at 1,050 deg.C used frequently. Accordingly, the surface to be formed with an element thereon is etched to remove the cutting strain, but the cutting strain on the back surface is intentionally retained. Thus, the retained cutting strain is gettering the infinitesimal fault and heavy metal impurity during the process to remarkably reduce the strain in the wafer. |
