| 摘要 |
PURPOSE:To obtain an inexpensive field effect transistor of high reliability by forming an insulated gate protecting diode in the substrate of a vertical FET. CONSTITUTION:A P type base 3 is formed in an N<-> type epitaxial layer 2 on an N<+> type Si substrate 1, an N type layer 4 is formed in the layer 3, and P<+> type layers 5, 3' are formed across the layers 4 and 3. When the electrode 8 of the layer 5 is connected to a gate electrode 7 and the layer 3' is connected to the source electrode 9, a bidirectional diode of P<+>NP<+> is formed. Then, when the impurity density and dimension of the layers 3', 4, 5 are altered, a diode for protecting the insulated gate having various breakdown voltage and withstand voltage can be formed, and adverse influence to the cost, quality and reliability in the conventional 2-chip type can be almost avoided. |
