| 摘要 |
The present invention relates to a field-effect transistor which is improved such that the linearity of mutual conductance gm is flattened over a wider range of gate bias. This field-effect transistor is a MESFET comprising a channel layer and a cap layer in Schottky-contact with a gate electrode. In particular, between the channel layer and the cap layer, one or more auxiliary layers having a doping concentration lower than that of the channel layer and higher than that of the cap layer are provided. The doping concentration of one or more auxiliary layers is set such that the doping profile of a laminated structure constituted by the channel layer, one or more auxiliary layers, and cap layer exponentially lowers from the channel layer toward the cap layer. According to this configuration, the depletion layer can effectively be controlled over a wider range of gate bias, the long gate effect and the like are suppressed, and the linearity of mutual conductance gm is improved.
|
