Semiconductor device
First Claim
1. A semiconductor device comprising:
- an SOI substrate having a semiconductor substrate, an insulating layer, and a semiconductor layer of a first conductivity type that are stacked in this order;
element isolation insulating films formed partially in a main surface of said semiconductor layer, with portions of said semiconductor layer interposed between said insulating layer and bottom surfaces of said element isolation insulating films;
a gate structure formed partially on said main surface of said semiconductor layer in an element formation region defined by said element isolation insulating films;
a pair of recesses formed in said element formation region, said recesses being formed in said main surface of said semiconductor layer in portions that are not covered by said gate structure, with a channel formation region under said gate structure interposed between said pair of recesses; and
source/drain regions formed in bottom surfaces of said recesses and having a second conductivity type that is different from said first conductivity type, said source/drain regions forming a pair, with said channel formation region interposed therebetween, and having bottom surfaces or depletion layers that reach said insulating layer.
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Accused Products
Abstract
A semiconductor device and its manufacturing method are provided which can properly avoid reduction of isolation breakdown voltage without involving adverse effects like an increase in junction capacitance. Impurity-introduced regions (11) are formed after a silicon layer (3) has been thinned through formation of recesses (14). Therefore n-type impurities are not implanted into the portions of the p-type silicon layer (3) that are located between the bottoms of element isolation insulating films (5) and the top surface of a BOX layer (2), which avoids reduction of isolation breakdown voltage. Furthermore, since the impurity-introduced regions (11) are formed to reach the upper surface of the BOX layer (2), the junction capacitance of source/drain regions (12) is not increased.
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Citations
11 Claims
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1. A semiconductor device comprising:
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an SOI substrate having a semiconductor substrate, an insulating layer, and a semiconductor layer of a first conductivity type that are stacked in this order;
element isolation insulating films formed partially in a main surface of said semiconductor layer, with portions of said semiconductor layer interposed between said insulating layer and bottom surfaces of said element isolation insulating films;
a gate structure formed partially on said main surface of said semiconductor layer in an element formation region defined by said element isolation insulating films;
a pair of recesses formed in said element formation region, said recesses being formed in said main surface of said semiconductor layer in portions that are not covered by said gate structure, with a channel formation region under said gate structure interposed between said pair of recesses; and
source/drain regions formed in bottom surfaces of said recesses and having a second conductivity type that is different from said first conductivity type, said source/drain regions forming a pair, with said channel formation region interposed therebetween, and having bottom surfaces or depletion layers that reach said insulating layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification