METHOD OF FABRICATING SEMICONDUCTOR DEVICE
First Claim
1. A method of fabricating a semiconductor device comprising the steps of:
- (a) forming a trench in a semiconductor substrate having a first semiconductor region of a first conductivity type, from a major surface of the semiconductor substrate in a depth direction thereof;
(b) forming a gate insulating film including a thermal oxide film and a deposition film over the internal surface of the trench;
(c) forming a gate electrode over the gate insulating film in the trench; and
(d) introducing, after said step (c), impurities into the semiconductor substrate to form a second semiconductor region of a second conductivity type; and
(e) introducing, after said step (c), impurities into the semiconductor substrate to form a third semiconductor region of the first conductivity type, the third semiconductor region being formed at a place deeper than the first semiconductor region, the second semiconductor region being formed between the third semiconductor region and the first semiconductor region in the depth direction.
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Accused Products
Abstract
In a method of fabricating a semiconductor device having a MISFET of trench gate structure, a trench is formed from a major surface of a semiconductor layer of first conductivity type which serves as a drain region, in a depth direction of the semiconductor layer, a gate insulating film including a thermal oxide film and a deposited film is formed over the internal surface of the trench, and after a gate electrode has been formed in the trench, impurities are introduced into the semiconductor substrate of first conductivity type to form a semiconductor region of second conductivity type which serves as a channel forming region, and impurities are introduced into the semiconductor region of second conductivity type to form the semiconductor region of first conductivity type which serves as a source region.
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Citations
21 Claims
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1. A method of fabricating a semiconductor device comprising the steps of:
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(a) forming a trench in a semiconductor substrate having a first semiconductor region of a first conductivity type, from a major surface of the semiconductor substrate in a depth direction thereof;
(b) forming a gate insulating film including a thermal oxide film and a deposition film over the internal surface of the trench;
(c) forming a gate electrode over the gate insulating film in the trench; and
(d) introducing, after said step (c), impurities into the semiconductor substrate to form a second semiconductor region of a second conductivity type; and
(e) introducing, after said step (c), impurities into the semiconductor substrate to form a third semiconductor region of the first conductivity type, the third semiconductor region being formed at a place deeper than the first semiconductor region, the second semiconductor region being formed between the third semiconductor region and the first semiconductor region in the depth direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of fabricating a semiconductor device comprising the steps of:
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(a) etching a semiconductor substrate having a first semiconductor region of a first conductivity type which serves as a drain region, and a silicon nitride film formed over a major surface of the semiconductor substrate, to form a trench from the major surface of the semiconductor substrate in a depth direction thereof;
(b) forming a gate insulating film including a thermal oxide film and a deposition film over the internal surface of the trench;
(c) forming a gate electrode over the gate insulating film in the trench;
(d) introducing, after said step (c), impurities into the semiconductor substrate to form a second semiconductor region of a second conductivity type which serves as a channel region; and
(e) introducing, after said step (c), impurities into the semiconductor substrate to form a third semiconductor region of the first conductivity type which serves as a source region, the third semiconductor region being formed at a place deeper than the first semiconductor region, the second semiconductor region being formed between the third semiconductor region and the first semiconductor region in the depth direction, and the silicon nitride film being removed at least after said step (b). - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method of forming a MISFET comprising the steps of:
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(a) etching a silicon nitride film formed over a major surface of a semiconductor substrate, and the semiconductor substrate, to form a trench from the major surface of the semiconductor substrate in a depth direction thereof;
(b) forming a gate insulating film of the MISFET including a thermal oxide film and a deposition film over the internal surface of the trench; and
(c) forming a gate electrode of the MISFET over the gate insulating film in the trench;
the silicon nitride film being removed at least after said step (b). - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification