| 摘要 |
PURPOSE:To provide an insulated gate type field effect transistor (IGFET) having sufficiently high charging capacity when used as a load element by forming a region having the same conducting type as the source and the drain regions and low impurity density while disposing the region between the source region and the drain region under a gate electrode. CONSTITUTION:A central portion as the element forming region of a P-type semiconductor substrate 21 is protruded, the thickness of the other portion is reduced, and N-type drain and source regions 22 and 23 are diffused in the central portion in space each other. Then, ion is implanted to the surface layer of the substrate 21 except the regions to form a P<+>-type channel cut region 28 is formed on the surface layer of the substrate 21, a thick field oxide film 27 is formed thereon, and a thin gate oxide film 25 is coated on the regions 22 and 23 surrounded by the film 27. Thereafter, a gate electrode 25 is bridged over the film 27 and is formed at the end on the film 26 as an FET. In this configuration an N<->-type region 24 having narrow width W is newly added between the regions 22 and 23 under the electrode 25 to prevent the decrease of the charging capacity. |
