| 摘要 |
PURPOSE:To form a GaAs epitaxial wafer with reduced series resistance by a method wherein a buffer layer, to be formed between a substrate crystal and an N type active layer, is constructed with two layers having different resistance values. CONSTITUTION:The first buffer layer 21 and the second buffer layer 22 are formed on a crystal substrate 1 having specific resistance of 1-2.5X10<3>OMEGAcm and on which and N type active layer 3 is formed. The specific resistance of the second buffer layer 22 is to be higher than that of the first buffer layer 21 and to be lower than that of the N type active layer 3. Then a mesa etching is selectively performed and an ohmic electrode 5 and a Schottky electrode 6 are formed. As a result, the series resistance of a GaAs device is reduced accurately, so the performance of the GaAs device such as rise in a cutoff frequency of a mixer diode and the like can be improved. A sufficient quantity of Te is to be added as an impurity in order to reduce the specific resistance. |
