| 摘要 |
PURPOSE:To obtain an element which is reliably operated by employing as an N-type impurity of AlAs/N-type GaAs superlattice structure Sn, S, Se or Te, thereby preventing the structure due to a heat treatment for activating from becoming orderless. CONSTITUTION:An AlAs/N-type superlattice structure layer 3 is formed through an undoped GaAs layer 2 on a semi-insulating GaAs substrate 1. The thickness of the AlAs layer of the layer for forming the layer 3 is of the degree that electrons are movable by a tunneling effect, and the sum of the thickness of the layer 3 becomes approx. 500Angstrom . Sn, S, Se or Te is used as the impurity for forming the GaAs layer as an N-type. After the layer 3 is formed, a gap 8 is held on the layer 3 to form a pair of N<+> type GaAs layer 4, and source and drain electrodes 5, 6 are formed on the layer 4. A gate electrode 7 is formed on the layer 3 between the layers 4. |
