| 摘要 |
PURPOSE:To uniform a current density in the channel width direction by introducing inpurity of the same conductivity type as a substrate into an area where is in contact with an indulating layer when a dent part is formed at the surface area of a semiconductor substrate, such dent area is filled with an insulating layer, and an MOS type transistor having a channel width of the specified value or less is formed at the surface surrounded by the dent part. CONSTITUTION:An SiO2 film 2 is deposited on the surface of a P type Si substrate 1 in both directions (100), and element forming area is covered with a resist film 3, the boron ion is implanted with such resist film used as the mask, and an impurity concentration is controlled so that an average concentration of surface impurity of the area ranged up to 0.3mum from the edge of channel becomes 1.3 times or more of that at the center of channel. Thereafter, the reactive ion etching is executed while leaving the film 3, only a layer 4 located under the film 3 among the ion implanting layer 4 is left, and the substrate 1 exposed in both sides of the film 3 is formed thin. This area is then filled with the SiO2 film 7, the film 3 is removed, thereby exposing the channel region where is in a high impurity concentration by the layer 4 in both edges under the film 3. |
