US 5,210,446 A · Substrate potential generating circuit employing Schottky diodes

Abstract

Substrate bias generating circuit for MIS semiconductor device comprising an oscillating circuit, a capacitor, an MOS transistor and a Schottky barrier diode. One end of the oscillating circuit is connected to a V.sub.ss terminal which provides a reference potential. The capacitor is connected at one end thereof to the other end of the oscillating circuit. The MOS transistor is connected between the V.sub.ss terminal and the other end of the capacitor, with the Schottky barrier diode being connected between a node located between the other end of the capacitor and the MOS transistor, and the substrate. The Schottky barrier diode is operated by the majority carrier, thereby enabling the majority charge to be directly pumped out of the substrate and into the terminal V.sub.ss through the Schottky barrier diode with stability without requiring an injection of the minority charge into the semiconductor substrate. The pumping of the charge out of the substrate is permitted by lowering the potential of the node through the oscillating circuit.

Claims7

Dependent claims

A semiconductor substrate potential generating circuit comprising:

an oscillating circuit;
a capacitor element including first and second capacitor plate and a dielectric therebetween;
a field-effect transistor having a control gate and a source-drain path connected at a node to one of the capacitor plates of said capacitor element and to a reference potential terminal;
said oscillating circuit being connected to the other capacitor plate of said capacitor element and to the reference potential terminal;
a Schottky barrier diode connected to the semiconductor substrate whose bias potential is to be controlled on its cathode side and to said one plate of said capacitor element on its anode side with the node associated with the source-drain path of said field-effect transistor being connected between said capacitor element and said Schottky barrier diode;
and
majority charge being pumped directly out of said substrate and into the reference potential terminal via said Schottky barrier diode without an injection of the minority charge into the substrate.

4 more elements

A semiconductor substrate potential generating system comprising:

a first semiconductor substrate potential generating circuit for pumping charge from a semiconductor substrate into a reference potential terminal;
a second semiconductor substrate potential generating circuit for pumping charge from the semiconductor substrate into the reference potential terminal;
a power-up holding circuit connected between the semiconductor substrate and the reference potential terminal and to one of said first and second semiconductor substrate potential generating circuits for controlling the pumping of charge from the substrate into the reference potential terminal by the said one of said first and second semiconductor substrate potential generating circuits;
and
logic means interconnected with said first and second semiconductor substrate potential generating circuits;
said first and second semiconductor substrate potential generating circuit being responsive to said logic means so as to operate in opposition to each other for providing charge pumping from the substrate into the reference potential terminal at enhanced efficiency.

3 more elements

Dependencies are inferred from the claim text.

Substrate potential generating circuit employing Schottky diodes

Life of this patent

Substrate potential generating circuit employing Schottky diodes

Life of this patent

Abstract

Claims7