Capacitor element

Abstract

Abstract PURPOSE:To prevent any fluctuation of floating capacity due to fluctuation of power supply voltage from happening by a method wherein, in a capacitor element wherein an insulating layer is laid between an N<+> layer in N<-> epitaxial layer and a metallic layer on a P<++> type Si substrate, a P<+> layer is provided on the bottom of the N<+> layer to supply the P<+> layer with bias voltage for insulating the N<+> layer from the P<+> layer. CONSTITUTION:A P<+> type layer 9 is provided between an N<+> layer 3 and an N<-> epitaxial layer 2 while an N<+> connecting layer 11 is provided in the N<-> layer 2 and then an electrode 10 connecting the layers 2 and 11 with each other is provided. The electrode 10 is supplied with bias VCC to insulate the P<+> layer 9 from the N<+> layer 3 while specific capacitor C1 is formed between electrodes 5a and 5b and then another capacitor C2 is formed between the N<+> layer 3 and the P<+> layer 9 further forming a floating capacitor VC between the epitaxial layer 2 and a substrate 1 grounded. The P<+> layer 9 is formed very thin to series-connect an extremely high resistor R to the capacitor C2 by pinch off effect so that any attenuation of transmitted signals may be neglected by R even if C2 becomes relatively large also any fluctuation of capacity between grounding may be neglected by high resistor R between C1 even if the capacitor VC is fluctuated by the fluctuation of power supply voltage. Besides as for C2, any fluctuationof voltage may be cancelled by means of equalizing the bias voltage fluctuation of the electrode 10 to that of the electrode 5b.

Inventors

• 👤 Junichi Hikita
• 👤 純一 疋田
• 👤 Shigeyoshi Hayashi
• 👤 林　成嘉

Bibliographic Details