Transistor channel
First Claim
1. A transistor device comprising:
- a substrate having a first region and a second region;
a first semiconductor layer of a first semiconductor material having a first portion over the first region and a second portion over the second region, the first portion being separated from the second portion wherein the first portion and second portion each extend respectively from a first bottom surface to a first top surface;
a second semiconductor layer of a second semiconductor material over the second portion of the first semiconductor layer, wherein the second semiconductor layer extends from a second bottom surface to a second top surface, the second bottom surface of the second semiconductor layer being disposed above the first top surface of the first portion of the first semiconductor layer;
a first transistor of a first conductivity type, the first transistor disposed within the first region and having a first set of source/drain regions formed in the first semiconductor layer and a first gate structure, wherein the first set of source/drain regions each comprise planar edges that extend to vertexes pointing towards a channel within the first transistor and include a main portion and a tip portion adjacent the vertexes, and wherein the tip portion comprises a superlattice structure and the main portion includes a non-superlattice structure, the superlattice structure alternating between individual layers of silicon germanium and silicon, both the silicon germanium and silicon having a same type of dopant and extending vertically in the tip portion from planar edge to planar edge; and
a second transistor of a second conductivity type, the second transistor disposed within the second region and having a second set of source/drain regions formed in the second semiconductor layer and a second gate structure;
wherein the second conductivity type is different than the first conductivity type, and the second semiconductor material is different from the first semiconductor material; and
wherein the first gate structure is at a first level above the substrate and the second gate structure is at a second level above the substrate, the second level greater than the first level and the first and second levels defined by a bottommost surface of the first and second gate structure respectively.
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Accused Products
Abstract
A transistor device includes a substrate having a first region and a second region, a first semiconductor layer of a first semiconductor material having a first portion over the first region and a second portion over the second region, the first portion being separated from the second portion, a second semiconductor layer of a second semiconductor material over the second portion of the first semiconductor layer, a first transistor of a first conductivity type, the first transistor disposed within the first region and having a first set of source/drain regions formed in the first semiconductor layer, and a second transistor of a second conductivity type, the second transistor disposed within the second region and having a second set of source/drain regions formed in the second semiconductor layer. The second conductivity type is different than the second conductivity type, and the second semiconductor material is different from the first semiconductor material.
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Citations
19 Claims
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1. A transistor device comprising:
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a substrate having a first region and a second region; a first semiconductor layer of a first semiconductor material having a first portion over the first region and a second portion over the second region, the first portion being separated from the second portion wherein the first portion and second portion each extend respectively from a first bottom surface to a first top surface; a second semiconductor layer of a second semiconductor material over the second portion of the first semiconductor layer, wherein the second semiconductor layer extends from a second bottom surface to a second top surface, the second bottom surface of the second semiconductor layer being disposed above the first top surface of the first portion of the first semiconductor layer; a first transistor of a first conductivity type, the first transistor disposed within the first region and having a first set of source/drain regions formed in the first semiconductor layer and a first gate structure, wherein the first set of source/drain regions each comprise planar edges that extend to vertexes pointing towards a channel within the first transistor and include a main portion and a tip portion adjacent the vertexes, and wherein the tip portion comprises a superlattice structure and the main portion includes a non-superlattice structure, the superlattice structure alternating between individual layers of silicon germanium and silicon, both the silicon germanium and silicon having a same type of dopant and extending vertically in the tip portion from planar edge to planar edge; and a second transistor of a second conductivity type, the second transistor disposed within the second region and having a second set of source/drain regions formed in the second semiconductor layer and a second gate structure;
wherein the second conductivity type is different than the first conductivity type, and the second semiconductor material is different from the first semiconductor material; and
wherein the first gate structure is at a first level above the substrate and the second gate structure is at a second level above the substrate, the second level greater than the first level and the first and second levels defined by a bottommost surface of the first and second gate structure respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A transistor device comprising:
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a gate stack on a substrate; a source region disposed in a first recess having two planar surfaces defined by a facet of the substrate having a first crystallographic orientation and angled inwards with respect to the gate stack towards a first vertex pointing towards a channel beneath the gate device; and a drain region disposed in a second recess having two planar surfaces defined by a facet of the substrate having the first crystallographic orientation and angled inwards with respect to the gate stack towards a second vertex pointing towards the channel; wherein a tip at the first vertex of the source region comprises a first superlattice structure having a plurality of individual layers that extend up to two planar surfaces of the first recess and the first vertex and a tip at the second vertex of the drain region comprises a second superlattice structure having a plurality of individual layers that extend up to the two planar surfaces of the second recess and the second vertex, wherein the source region and the drain region adjacent the tip of the respective first vertex and second vertex are non-superlattice structure. - View Dependent Claims (14, 15)
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16. A semiconductor device comprising:
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a first transistor, the first transistor comprising; a first gate stack disposed over a substrate and on a top surface of a first semiconductor layer; a first source epitaxial structure doped with a first dopant of boron and filling a first recess in the first semiconductor layer, the first recess having two planar surfaces defined by a facet of the substrate and extending in to a vertex pointing towards a channel beneath the first gate stack, wherein a tip of the vertex of the first source epitaxial structure has a higher concentration of the first dopant than any other portion of the first source epitaxial structure; and a first drain epitaxial structure doped with the first dopant and filling a second recess in the first semiconductor layer, the second recess having two planar surfaces defined by a facet of the substrate and extending in to a vertex pointing towards the channel, wherein a tip of the vertex of the first drain epitaxial structure has a higher concentration of the first dopant than any other portion of the first drain epitaxial structure, wherein the tip of the vertex of the first source epitaxial structure is spaced apart from the tip of the vertex of the first drain epitaxial structure by a first distance; and a second transistor, the second transistor comprising a second gate stack over the substrate and on a top surface of a second semiconductor layer, a portion of the first semiconductor layer underlying the second semiconductor layer; a second source epitaxial structure doped with a second dopant and filling a third recess in the second semiconductor layer; a second drain epitaxial structure doped with the second dopant and filling a fourth recess in the second semiconductor layer, wherein a bottom surface of the second semiconductor layer is spaced a greater height from a top surface of the substrate than the top surface of the first semiconductor layer under the first gate stack. - View Dependent Claims (17, 18, 19)
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Specification