Pseudo-Schottky diode
First Claim
1. A semiconductor device comprising:
- a source region of a first conductivity type;
a body region of a second conductivity type opposite to said first conductivity type adjacent said source region;
a drain region of said first conductivity type adjacent said body region; and
a gate separated by an insulating layer from a channel region of said body region,wherein said source region, said body region and said drain region are formed in a semiconductor chip, said gate being positioned in a trench which is formed at a surface of said chip, said source region, said body region and said gate being shorted together and biased at a first voltage and said drain region being biased at a second voltage, said first and second voltages being established such that a junction between said body and said drain is forward-biased.
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Accused Products
Abstract
An N-channel MOSFET is fabricated with its source, body and gate connected together and biased at a positive voltage with respect to its drain. The resulting two-terminal device functions generally in the manner of a diode but has a significantly lower turn-on voltage than a conventional PN diode. The device is therefore referred to as a "pseudo-Schottky diode". Pseudo-Schottky diodes have numerous uses, but they are particularly useful when connected to shunt current from a conventional PN diode or MOSFET and thereby prevent such conditions as snapback and latchup which can result from the storage of minority carriers in a forward-biased PN junction. Also, because the pseudo-Schottky diode is a majority carrier device, the diode recovery time, amount of stored charge, and peak reverse current are much lower than in a conventional PN diode.
139 Citations
14 Claims
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1. A semiconductor device comprising:
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a source region of a first conductivity type; a body region of a second conductivity type opposite to said first conductivity type adjacent said source region; a drain region of said first conductivity type adjacent said body region; and a gate separated by an insulating layer from a channel region of said body region, wherein said source region, said body region and said drain region are formed in a semiconductor chip, said gate being positioned in a trench which is formed at a surface of said chip, said source region, said body region and said gate being shorted together and biased at a first voltage and said drain region being biased at a second voltage, said first and second voltages being established such that a junction between said body and said drain is forward-biased. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A semiconductor device formed within a transistor comprising:
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a source region of a first conductivity type; a body region of a second conductivity type adjacent said source region; a drain region of said first conductivity type adjacent said body region; a first gate separated by a first insulating layer from a channel region of said body region, and a second gate separated by a second insulating layer from a channel region of said body region, wherein said source region, said body region and said second gate are shorted together and biased at a first voltage and said drain region is biased at a second voltage, said first and second voltages being established such that a junction between said body and said drain is forward-biased.
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Specification