High withstand voltage M I S field effect transistor and semiconductor integrated circuit
First Claim
1. A high withstand voltage MIS field effect transistor comprising a second conductivity type well region formed on a first conductivity type semiconductor substrate;
- a MOS portion providing a pair of first conductivity type first base layers formed in an outer portion of the well region, second conductivity type source layers formed in the first base layers and a gate electrode disposed over the source layers through an insulating layer;
a drain portion providing a second conductivity type drain layer formed in an inner portion of said well region, a first conductivity type second base layer formed in said well region between said MOS portion and said drain portion; and
a field oxide film formed on the surface of said second base layer.
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Accused Products
Abstract
A semiconductor integrated circuit device is provided in which a highly reliable and low cost intelligent power semiconductor is mounted on the same substrate as that of a control circuit having a logic element, such as a low withstand voltage CMOS etc., and high withstand voltage and high current output MIS field effect transistor. A high withstand voltage MOSFET is composed of a vertical MOS portion 25 formed in one side of a laterally widened well layer 2 and a drain portion formed in the other side thereof and a second base layer 4 is formed on the surface of the well layer 2. Accordingly, a depletion layer widened just under the MOS portion 25 and the second base layer 4 develops a JFET effect at OFF time thereby realizing a high withstand voltage and reliability is provided since the generation of hot carriers can be prevented by the second base layer 4.
52 Citations
22 Claims
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1. A high withstand voltage MIS field effect transistor comprising a second conductivity type well region formed on a first conductivity type semiconductor substrate;
- a MOS portion providing a pair of first conductivity type first base layers formed in an outer portion of the well region, second conductivity type source layers formed in the first base layers and a gate electrode disposed over the source layers through an insulating layer;
a drain portion providing a second conductivity type drain layer formed in an inner portion of said well region, a first conductivity type second base layer formed in said well region between said MOS portion and said drain portion; and
a field oxide film formed on the surface of said second base layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 21, 22)
- a MOS portion providing a pair of first conductivity type first base layers formed in an outer portion of the well region, second conductivity type source layers formed in the first base layers and a gate electrode disposed over the source layers through an insulating layer;
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9. A high withstand voltage MIS field effect transistor having a second conductivity type well region formed on a first conductivity type semiconductor substrate;
- a MOS portion providing in an outer portion of the well region, a second conductivity type source layer formed in a base layer and a gate electrode disposed through an insulating gate film over the source layer and an area of said well region;
a drain portion providing a second conductivity type drain layer formed in an inner portion of said well region;
a first conductivity type offset region formed in said well region between said MOS portion and said drain portion; and
a conducting layer disposed through an insulating film over said offset region. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18)
- a MOS portion providing in an outer portion of the well region, a second conductivity type source layer formed in a base layer and a gate electrode disposed through an insulating gate film over the source layer and an area of said well region;
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19. A high withstand voltage MIS field effect transistor having a second conductivity type well region formed on a first conductivity type semiconductor substrate;
- a MOS portion providing, in an outer portion of the well region, a first conductivity type base layer, a second conductivity type source layer formed in the base layer and a gate electrode disposed through an insulating gate film over the source layer and said well region;
a drain portion providing a second conductivity type drain layer formed in an inner portion of said well region, said MOS portion being generally concentrically formed with said drain portion as the center, at least one portion of said well region, said MOS portion and said drain portion being a withstand voltage region capable of enduring a desired withstand voltage with reference to the distance between said MOS portion and said drain portion and having a voltage transferring means capable of transferring the voltage in the withstand voltage region to said well region; andsaid voltage transferring means including a plurality of field plates spaced from each other and disposed generally concentrically about said drain portion and within said MOS portion and contacting said withstand voltage region to provide voltage control thereover. - View Dependent Claims (20)
- a MOS portion providing, in an outer portion of the well region, a first conductivity type base layer, a second conductivity type source layer formed in the base layer and a gate electrode disposed through an insulating gate film over the source layer and said well region;
Specification