| 摘要 |
PURPOSE:To increase the current amplification factor gm by a method wherein channels are provided above and below the diffusion layer of a gate, while the width of the channel is made twofold without changing the chip dimensions. CONSTITUTION:A p<+> gate 8 is formed on a p type Si substrate 1, using an oxide film 11 as a mask. The mask is removed to lay an n<-> epitaxial layer, and an n<+> source 5 and a drain 4 are formed, using an oxide film 12 as a mask. Other than this, the p<+> gate 8 may be formed by the ion injection method. On changing the width of the channels above and below the gate 8 or changing the density in the upper and lower channels, or providing the second gate in the upper channel through an insulating film, a J-FET with higher gm can be obtained. |
