| 摘要 |
PURPOSE:To obtain a GTO thyristor taking short turn off time even if the thickness of N-type base layer is increased by a method wherein a damaged layer for carrier trapping is formed in a specified region of an N-type base layer by implanting the region with ions such as of protons, etc. CONSTITUTION:A damaged layer 29 for carrier trapping is formed in the specified region of an N-type base layer 21. When the region is implanted with ion such as proton etc. so that the center Rp of range may be positioned on the part near the very center of the N-type base layer 21 from the main surface, the concentration in the region several mum around the terminating region of the range is concentratedly increased while decreasing the concentration in other passed through regions. Thus, the damaged layer 29 can be formed concentratedly. The depth of range can be determined by the implanted energy. In order to implant, e.g., protons in the depth of 100mum, around 3MeV of energy must be expended. Argon, He, etc., other than proton may be applicable, but proton is recommended since high energy must be expended to implant any massive atoms in a deep depth. |
