| 摘要 |
A monolithic capacitor formed on a semiconductor substrate (201) has a large parasitic capacitance (Cpar) from the bottom plate (205) of the capacitor to the substrate. The value of this parasitic capacitance is reduced by connecting it in series with a smaller substrate capacitance (Csub). The substrate capacitance dominates the total value, if it is much smaller than the bottom plate capacitance. The small substrate capacitance under the monolithic capacitor is produced by adding under the monolithic capacitor a semiconductor well (202') of a different type than a semiconductor substrate or body on which the monolithic capacitor is formed. This well is either left floating or connected with a high-value resistor to an AC ground. <IMAGE> |
