| 摘要 |
PURPOSE:To generate the distribution of impurity concentration in source and drain regions, and to avoid electric-field concentration by forming a projecting section having thin thickness to the bottom of a gate electrode and implanting impurity ions while using the electrode as a mask when the gate electrode consisting of polycrystalline Si is provided on a semiconductor substrate. CONSTITUTION:A thick field SiO2 film 2 is formed to the peripheral section of an N type Si substrate 1, a thin gate SiO2 film 3 is applied on the substrate 1 surrounded by the film 2, and a polycrystalline Si film is deposited on the whole surface containing the film 3. A polycrystalline Si electrode 4 is shaped under a photo-resist film 5 through etching while using the photo-resist film 5 as a mask, the film 5 is replaced with a film 5' in size smaller than the film 5, and the electrode 4 is changed into an electrode 4', a lower side section thereof is projected, through second etching. P<+> ions are implanted while employing the electrode 4' as a mask, a region having shallow depth and low impurity concentration is formed under the projecting section, and deep P type source and drain regions 5, 6 having high concentration are shaped in regions conneted to said region. |
