| 摘要 |
PURPOSE:To reduce the irregularity of electric characteristics of a semiconductor device by once damaging a crystal of silicon by implanting rare gas ions, and then again returning it by a short time heat treatment to a polycrystal, thereby making uniform crystal grain sizes of a polycrystalline silicon layer. CONSTITUTION:A polycrystalline silicon layer 5 is formed on a semiconductor wafer 10 by a vapor phase growth method, and argon ions 11 are then implanted to the layer 5. Then, the ions 11 are implanted in a normal distribution state into the layer 5 to damage the crystal of the layer 4 to convert it to an amorphous silicon layer 7. Then, when a halogen lamp is irradiated for a short time in argon gas to anneal it, the layer 7 is returned to a polycrystalline silicon layer 8 with a uniform bonding strength of crystal grain size and atoms. Further, n-type impurity ions 12 are similarly implanted into the layer 8 to perform similar heat treatment in argon gas. The layer 8 becomes an n-type polycrystalline silicon layer 9 by this heat treatment, and the part adjacent to the layer 9 in the layer 4 forms an n-type impurity layer 6.
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