| 摘要 |
PURPOSE:To obtain a high electron mobility semiconductor device (HEMT) which has hetero junction of N type Al-GaAs-GaAs having excellent low temperature operating characteristics by specifying the lateral rate (x value) of AlAs of an N type AlGaAs layer to the specific value. CONSTITUTION:Even if AlxGa1-xAs having lower than 0.25 of x value is cooled to the vicinity of liquefied nitrogen temperature, frozen state of electrons hardly occurs. When the (x) value is selected to the range from the upper limit of the maximum value that the activating energy of donor level in AlxGa1-xAs becomes substantially equal to the activating energy of the donor level of GaAs and the lower limit of the minimum value that gives Ec (=discontinuous energy difference of conductor) larger than the burning energy (KT) of a lattice, the HEMT having extremely good characteristic can be manufactured. When silicon is used as the donor impurity, the (x) value is selected from the range of 0.18- 0.03. |
