| 摘要 |
PURPOSE:To form at the same time with a capacitor beam structure of small area and large capacitance by forming a double-stage capacitors on the same semiconductor substrate without alternating the manufacturing process. CONSTITUTION:An oxide film 11, a poly Si film serving as the lower electrode 12, an Si3N4 film serving as the lower dielectric film 13, a poly Si film serving as the intermediate electrode 14, an Si3N4 film serving as the upper dielectric film 15, an Al film serving as the upper electrode 16, and the final protection film 19 are successively formed on an N-type Si substrate 22. The lower electrode 12 is connected to the upper electrode 16 with electrode wirings 29' and 29''. Connection to the outside is made at the part of bonding pads 20' and 20''. This makes a capacitor consisting of the lower electrode 12, lower dielectric film 13, and intermediate film 14 and a capacitor consisting of the upper electrode 16, upper dielectric film 15, and intermediate electrode 14 to be connected in parallel. Accordingly, the electrostatic capacitance per occupation area on the semiconductor substrate is about twice as large as the conventional capacitance of one-stage thin film. |
