| 摘要 |
PURPOSE:To enable to obtain the excellent characteristic of noise index by a method wherein a channel current is controlled by impressing a voltage between the conductive semiconductor substrate of the FET and the source electrode. CONSTITUTION:An N type GaAs active layer 12 is mounted on the N<+> GaAs semiconductor substrate 10 via I type GaAs buffer layer 11, resulting in the construction of an FET. In opposition to a source electrode 13, a positive voltage is impressed on a drain electrode 14, a negative one on a gate electrode 15 and further a negative one on a substrate ohmic electrode 16. As a result, a depletion layer 17 expands as shown in the figure, and then can independently control the drain-source current by variation in the voltage impressed on the electrode 15 and the electrode 16. Since the unstable region 18 at the interface enters in the depletion layer 17, the improvement of the characteristic of NF (noise index) can be contrived. |
