| 摘要 |
PURPOSE:To reduce an area occupied by a memory-transistor, and to improve the degree of integration by forming a floating-gate into an epitaxial layer on a semiconductor substrate. CONSTITUTION:A resist 3 is formed to a P-type Si substrate 1, As is implanted, an N<+> diffusion layer 2 is shaped through heat treatment, the resist 3 is removed, a P-type Si epitaxial layer 4 and insulating films 5 consisting of SiO2 are formed, and an N<+> diffusion layer 7 is shaped. A groove is dug up to the N<+> diffusion layer 2 to the P-type Si epitaxial layer 4, and an SiO2 film 8 is grown on the upper surfaces of N<+> diffusion layers 7a, 7b and the side wall and base of the groove. The groove is buried with polycrystalline silicon containing As to form a floating-gate 9, an SiO2 film 10 is shaped through a thermal oxidation method, and a control-gate 11 is shaped through photoetching. An insulating film layer 12 is formed, and contact-holes are shaped with the object of the connection of electrodes and the obtaining of electric connection to the N<+> diffusion layer 2. The electrodes 13 are formed to the contact-holes and the upper surface of the insulating film layer 12, thus acquiring a semiconductor device. |
