Semiconductor device and a method of manufacturing the same
First Claim
1. A semiconductor device including a trench gate type MISFET,the trench gate type MISFET comprising:
- a semiconductor substrate of a first conductivity type;
a first semiconductor layer of the first conductivity type formed on the semiconductor substrate and serving as a drain region of the MISFET;
a first, a second and a third trench formed on the top surface of the first semiconductor layer (FIGS. 9-11),the first trench arranged, in a first direction, adjacent to the second trench such that a distance, in the first direction, of a first region of the top surface is defined by the first trench and the second trench (FIG. 26),the second trench arranged, in the first direction, adjacent to the third trench such that a distance, in the first direction, of the second region of the top surface is defined by the second trench and the third trench (FIG. 26);
a gate insulating film of the MISFET formed on an inner surface of the trenches;
a gate electrode of the MISFET formed on the gate insulating film in the trench;
a second semiconductor region (13) of a second conductivity type opposite to the first conductivity type formed at the first region and on the first semiconductor layer,the second semiconductor region (13) being in contact with the first and the second trench and serving as a channel forming region of the MISFET;
a third semiconductor region (13) of the second conductivity type opposite to the first conductivity type formed at the second region and on the first semiconductor layer,the third semiconductor region (13) being in contact with the second and the third trench such that the third semiconductor region (13) is formed to be in contact with a bottom surfaces of the second and the third trench; and
a fourth semiconductor region of the first conductivity type formed at the first region and on the second semiconductor layer and serving as a source region of the MISFET.
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Accused Products
Abstract
A technology is provided to reduce ON-resistance, and the prevention of punch through is achieved with respect to a trench gate type power MISFET. Input capacitance and a feedback capacitance are reduced by forming a groove in which a gate electrode is formed so as to have a depth as shallow as about 1 μm or less, a p− type semiconductor region is formed to a depth so as not to cover the bottom of the groove, and a p-type semiconductor region higher in impurity concentration than the p−type semiconductor region is formed under a n+type semiconductor region serving as a source region of the trench gate type power MISFET, causing the p-type semiconductor region to serve as a punch-through stopper layer of the trench gate type power MISFET.
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Citations
3 Claims
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1. A semiconductor device including a trench gate type MISFET,
the trench gate type MISFET comprising: -
a semiconductor substrate of a first conductivity type; a first semiconductor layer of the first conductivity type formed on the semiconductor substrate and serving as a drain region of the MISFET; a first, a second and a third trench formed on the top surface of the first semiconductor layer ( FIGS. 9-11 ),the first trench arranged, in a first direction, adjacent to the second trench such that a distance, in the first direction, of a first region of the top surface is defined by the first trench and the second trench ( FIG. 26 ),the second trench arranged, in the first direction, adjacent to the third trench such that a distance, in the first direction, of the second region of the top surface is defined by the second trench and the third trench ( FIG. 26 );a gate insulating film of the MISFET formed on an inner surface of the trenches; a gate electrode of the MISFET formed on the gate insulating film in the trench; a second semiconductor region (13) of a second conductivity type opposite to the first conductivity type formed at the first region and on the first semiconductor layer, the second semiconductor region (13) being in contact with the first and the second trench and serving as a channel forming region of the MISFET; a third semiconductor region (13) of the second conductivity type opposite to the first conductivity type formed at the second region and on the first semiconductor layer, the third semiconductor region (13) being in contact with the second and the third trench such that the third semiconductor region (13) is formed to be in contact with a bottom surfaces of the second and the third trench; and a fourth semiconductor region of the first conductivity type formed at the first region and on the second semiconductor layer and serving as a source region of the MISFET. - View Dependent Claims (2, 3)
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Specification