| 摘要 |
PURPOSE:To make it possible to form a required capacitor element or a wiring bus line in parallel with the fablication of an MOS transistor, by forming the capacitor element beneath the aluminum wiring bus line, thereby increasing the integration of density of a circuit by saving a space, and increasing the capacitance by using a high dielectric constant material such as silicon nitride as the capacitor element. CONSTITUTION:On the main surface of a substrate 10, an SiO2 film 16 is formed. A gate electrode 18 made of polycrystalline silicon is formed between the region of a source 12 and the region of a drain 14. A polycrystalline conductor layer 20 is formed on an Al wiring- bus-line forming region on the film 16. Thereafter, etching is performed with a silicon nitride film formed on the surface of the substrate 10 as a mask. A silicon nitride film 22 is formed only on the conductor layer 20. Then, the entire surface of the substrate 10 is coated with an SiO2 film 24 as an interlayer insulating film. When a capacitor element is formed by utilizing the silicon nitride film 22, the film 24 is removed and a hole 30 having about the same size of the film 22 is formed by etching, when contact holes 26 and 28 are formed in the insulating film 24. Then, Al electrodes 32, 34 and 36 are formed. The electrodes 32 and 34 form source and drain electrodes. The electrode 36, the silicon nitride film 22 and the conductor layer 20 constitute the capacitor element. |
