| 摘要 |
First, a front surface element structure is formed on the front surface side of an n - -type semiconductor substrate. Then defects (12) are formed throughout the entire n - -type semiconductor substrate by electron beam irradiation and furnace annealing, so as to adjust the carrier lifetime. Next, the thickness of the n - -type semiconductor substrate is decreased by grinding the rear surface of the n - -type semiconductor substrate. Then n-type impurities are ion-implanted from the ground rear surface side of the n - -type semiconductor substrate, and an n + -type cathode layer (4) is formed on the surface layer of the rear surface of the n - -type semiconductor substrate. Thereafter, hydrogen ions are ion-implanted (14) from the rear surface side of the n - -type semiconductor substrate, and a hydrogen implanted region having a hydrogen concentration higher than the hydrogen concentration of a bulk substrate is formed on the surface layer of the rear surface of the n - -type semiconductor substrate. Then a cathode electrode is formed after activating the n + -type cathode layer (4) by laser annealing. By so doing, carrier lifetime can be locally controlled at low cost, without increasing leak current or contaminating the manufacturing line. |
