US 5,844,280 A · Device for protecting a semiconductor circuit

Abstract

A protection device for protecting a semiconductor circuit from positive and negative overvoltage such as static electrical discharges. A p-type substrate is provided having a pair of spaced apart n-type regions formed therein. Each of the spaced apart n-type regions has a p.sup.+ region and an n.sup.+ region formed therein. Each of the spaced apart n-type regions also includes an n.sup.+ drain tap which has a portion in contact with the substrate. The n.sup.+ region and one p.sup.+ region of one of the spaced apart n-type regions are connected to a terminal of a semiconductor circuit. The n.sup.+ region and p.sup.+ regions of the other n-type region are connected to a power voltage of the semiconductor device. A insulated gate is formed on a p-type semiconductor substrate, and is in contact with both n+ drain taps. The gate is grounded. The bilateral protection device of the present invention protects the semiconductor circuit against positive and negative overvoltages.

Claims12

Dependent claims

A device for protecting a semiconductor circuit, comprising:

a semiconductor substrate of a first conductive type;
a first region of a second conductive type formed in the substrate and having a first region of a third conductive type and a first region of a fourth conductive type formed therein;
a second region of the second conductive type formed in the substrate and spaced apart from the first region of the second conductive type, and having a second region of the third conductive type and a second region of the fourth conductive type formed therein;
a third region of the fourth conductive type formed in the substrate and in contact with the first region of the second conductive type;
a fourth region of the fourth conductive type formed in the substrate and in contact with the second region of the second conductive type;
and
a gate formed on the substrate to form a MOS transistor having the third region of the fourth conductive type and the fourth region of the fourth conductive type as a source and a drain respectively.

4 more elements

A device for protecting a semiconductor circuit, comprising:

a semiconductor substrate of a first conductive type;
a first second-conductive-type region formed in the substrate and having a first region of the first conductive type and a second second-conductive-type region formed therein;
a third second-conductive-type region formed in the substrate and spaced apart from the first second-conductive-type region, and having a second region of the first conductive type and a fourth second-conductive-type region formed therein;
a fifth second-conductive-type region formed in the substrate and in contact with the first second-conductive-type region;
and
a sixth second-conductive-type region formed in the substrate and in contact with the third second-conductive-type region,
wherein the second, the fourth, the fifth and the sixth second-conductive-type regions have higher doping densities than the first and the third second-conductive-type regions and the first and the second regions of the first conductive type have higher doping densities than the substrate, and wherein the first and the third second-conductive-type regions are located between the second second-conductive-type region and the fourth second-conductive-type region and the second region of the first conductive type, respectively.

4 more elements

Dependencies are inferred from the claim text.

Device for protecting a semiconductor circuit

Life of this patent

Device for protecting a semiconductor circuit

Life of this patent

Abstract

Claims12