| 摘要 |
PROBLEM TO BE SOLVED: To prevent a semiconductor wafer from deteriorating in peak current density, even if it is subjected to a thermal treatment. SOLUTION: An I-type compound semiconductor layer 14 which is different in lattice constant from an N<+> -type compound semiconductor layer 13 and a P<+> -type compound semiconductor layer 15 and high in chemical bonding power is provided between the compound semiconductor layer 13 and 15, whereby N-type impurities and P-type impurities are restrained from being diffused through an interface between the layers 13 and 15, when a thermal treatment is carried out for processing a wafer. So that an impurity concentration gradient is kept steep in a semiconductor wafer of this constitution, and the semiconductor wafer is hardly deteriorated in peak tunnel current density. The I layer 14 is formed of Inx Ga1-x As or Inx Ga1-x Asy P1-y , large in chemical bonding power and different in lattice constant from GaAs, whereby N-type impurities and P-type impurities are restrained from being diffused through lattice defects, and a tunnel peak current is hardly dropped in density. |
