| 摘要 |
PURPOSE:To prevent a time-wise reduction of a drain current at the time of operating at a low temperature by providing a GaAs channel layer and an electron supply layer made of strained superlattice of group II-VI compound. CONSTITUTION:ZnTe is selected as first group II-VI compound having smaller electron affinity than that of gallium arsenide single crystal, and ZnSe is selected as second group II-VI compound having larger electron affinity than that of the group II-VI compound having substantially equal lattice constant to that of the GaAs single crystal, a thin layer having 100Angstrom or less of thickness made of nondoped ZnTe and a thin layer having 100Angstrom or less of thickness made of ZnSe added with an N-type impurity are alternately repeatedly epitaxially grown on a high purity GaAs channel layer 2 thereby to form a superlattice structure, and which is used as an electron supply layer 10. Thus, the time-wise reduction of a drain current is eliminated at the time of operating it at a low temperature. |
