US6339232B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device
Assignee: Kioxia Corp
•
Filing: 2000-09-20
•
Granted: 2002-01-15
•
Expires: 2020-09-20
Abstract
Abstract There is provided a semiconductor device in which gate electrodes of both an n-channel field effect transistor and a p-channel field effect transistor constituting a complementary field effect transistor are made of the same material and threshold voltages of both are sufficiently lowered. In the semiconductor device including an n-channel MOSFET and a p-channel MOSFET which constitute a CMOS structure, the gate electrode of the n-channel MOSFET and the gate electrode of the p-channel MOSFET are made of the same material, at least a part of a channel region of the n-channel MOSFET is formed in a strained Si layer, at least a part of a channel region of the p-channel MOSFET is formed in an SiGe layer, the work function of the material making the gate electrodes is higher than an energy difference between the conduction band edge of the strained Si layer and the vacuum level, and is lower than an energy difference between the valence band edge of the SiGe layer and the vacuum level.
Inventors
- 👤 Shinichi Takagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:31
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/201; H10D86/01
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
226 words
A semiconductor device comprising: a semiconductor substrate; an n-channel field effect transistor formed on the semiconductor substrate; and a p-channel field effect transistor formed on the semiconductor substrate, the n-channel field effect transistor and the p-channel field effect transistor constituting a complementary field effect transistor, wherein a gate electrode of the n-channel field effect transistor and a gate electrode of the p-channel field effect transistor are made of a same material, wherein a channel region of the n-channel field effect transistor is made of a material which contains at least of Si and in which an energy difference between a conduction band edge and a vacuum level is higher than that of bulk Si, and a channel region of the p-channel field effect transistor is made of a material which contains at least of Si and in which an energy difference between a valence band edge and the vacuum level is lower than that of bulk Si, and wherein a work function of the material making the gate electrodes is higher than the energy difference between the conduction band edge of the material making the channel region of the n-channel field effect transistor and the vacuum level, and is lower than the energy difference between the valence band edge of the material making the channel region of the p-channel field effect transistor and the vacuum level.
Claim 2
Dependent Claim
226 words
A semiconductor device comprising: a semiconductor substrate; an n-channel field effect transistor formed on the semiconductor substrate; and a p-channel field effect transistor formed on the semiconductor substrate, the n-channel field effect transistor and the p-channel field effect transistor constituting a complementary field effect transistor, wherein a gate electrode of the n-channel field effect transistor and a gate electrode of the p-channel field effect transistor are made of a same material, wherein a channel region of the n-channel field effect transistor is made of a material which contains at least of Si and in which an energy difference between a conduction band edge and a vacuum level is higher than that of bulk Si, and a channel region of the p-channel field effect transistor is made of a material which contains at least of Si and in which an energy difference between a valence band edge and the vacuum level is lower than that of bulk Si, and wherein a work function of the material making the gate electrodes is higher than the energy difference between the conduction band edge of the material making the channel region of the n-channel field effect transistor and the vacuum level, and is lower than the energy difference between the valence band edge of the material making the channel region of the p-channel field effect transistor and the vacuum level.
Claim 3
Dependent Claim
26 words
A semiconductor device according to claim 1 , wherein tensile stress is introduced into the material making the channel region of the n-channel field effect transistor.
Claim 4
Dependent Claim
26 words
A semiconductor device according to claim 1 , wherein compressive stress is introduced into the material making the channel region of the p-channel field effect transistor.
Claim 5
Dependent Claim
24 words
A semiconductor device according to claim 1 , wherein the material making the channel region of the n-channel field effect transistor is strained Si.
Claim 6
Dependent Claim
23 words
A semiconductor device according to claim 1 , wherein the material making the channel region of the p-channel field effect transistor is SiGe.
Claim 7
Dependent Claim
81 words
A semiconductor device according to claim 1 , wherein the Fermi level E F of the gate electrode material is ( 4 E v2 +E c1 )/5 or less and (E v2 + 4 E c1 )/5 or less, E v2 is the valence band edge of the material making the channel region of the p-channel field effect transistor and E c1 is the conduction band edge of the material making of the channel region of the n-channel field effect transistor.
Claim 8
Dependent Claim
67 words
A semiconductor device according to claim 1 , wherein the Fermi level E F of the gate electrodematerial is substantially (E v2 +E c1 )/2, E v2 is the valence band edge of the material making the channel region of the p-channel field effect transistor and E c1 is the conduction band edge of the material making of the channel region of the n-channel field effect transistor.
Claim 9
Dependent Claim
61 words
A semiconductor device according to claim 1 , wherein E c1 of the channel material of the n-channel MOSFET is higher than (E v0 + 9 E c0 )/10 and not higher than (E v0 +E c0 )/2, E v0 is the valence band edge of the bulk Si and E c0 is the conduction band edge of the bulk Si.
Claim 10
Dependent Claim
61 words
A semiconductor device according to claim 1 , wherein E v2 of the channel material of the p-channel MOSFET is not less than (E v0 +E c0 )/2 and less than ( 9 E v0 +E c0 )/10, E v0 is the valence band edge of the bulk Si and E c0 is the conduction band edge of the bulk Si.
Claim 11
Dependent Claim
168 words
A semiconductor device comprising: a semiconductor substrate; an n-channel field effect transistor formed on the semiconductor substrate; and a p-channel field effect transistor formed on the semiconductor substrate, the n-channel field effect transistor and the p-channel field effect transistor constituting a complementary field effect transistor, wherein a gate electrode of the n-channel field effect transistor and a gate electrode of the p-channel field effect transistor are made of a same material, wherein at least a part of a channel region of the n-channel field effect transistor is formed in a strained Si layer, wherein at least a part of a channel region of the p-channel field effect transistor is formed in a first SiGe layer, and wherein a work function of the material making the gate electrodes is higher than an energy difference between a conduction band edge of the strained Si layer and a vacuum level, and is lower than an energy difference between a valence band edge of the first SiGe layer and the vacuum level.
Claim 12
Dependent Claim
168 words
A semiconductor device comprising: a semiconductor substrate; an n-channel field effect transistor formed on the semiconductor substrate; and a p-channel field effect transistor formed on the semiconductor substrate, the n-channel field effect transistor and the p-channel field effect transistor constituting a complementary field effect transistor, wherein a gate electrode of the n-channel field effect transistor and a gate electrode of the p-channel field effect transistor are made of a same material, wherein at least a part of a channel region of the n-channel field effect transistor is formed in a strained Si layer, wherein at least a part of a channel region of the p-channel field effect transistor is formed in a first SiGe layer, and wherein a work function of the material making the gate electrodes is higher than an energy difference between a conduction band edge of the strained Si layer and a vacuum level, and is lower than an energy difference between a valence band edge of the first SiGe layer and the vacuum level.
Claim 13
Dependent Claim
57 words
A semiconductor device according to claim 10 , wherein the n-channel field effect transistor includes a second SiGe layer which has the same composition ratio as the first SiGe layer and is disposed between the semiconductor substrate and the strained Si layer, and tensile stress is introduced into the strained Si layer from the second SiGe layer.
Claim 14
Dependent Claim
104 words
A semiconductor device according to claim 10 , wherein the n-channel field effect transistor includes a second SiGe layer which has a Ge concentration higher than the first SiGe layer and is disposed between the semiconductor substrate and the strained Si layer, the p-channel field effect transistor includes a third SiGe layer which has the same composition ratio as the second SiGe layer and is disposed between the semiconductor substrate and the first SiGe layer, tensile stress is introduced into the strained Si layer from the second SiGe layer, and compressive stress is introduced into the first SiGe layer from the third SiGe layer.
Claim 15
Dependent Claim
27 words
A semiconductor device according to claim 12 wherein the p-channel field effect transistor includes a Si layer between the first SiGe layer and the third SiGe layer.
Claim 16
Dependent Claim
29 words
A semiconductor device according to claim 12 , wherein the first SiGe layer composes Si 1−x Ge x and the second SiGe layer composes Si 1−y Ge y (y>x).
Claim 17
Dependent Claim
33 words
A semiconductor device according to claim 1 , wherein the gate electrode is made of a material selected from the group consisting of metal, doped p-type polycrystalline Ge, and doped p-type polycrystalline SiGe.
Claim 18
Dependent Claim
33 words
A semiconductor device according to claim 10 , wherein the gate electrode is made of a material selected from the group consisting of metal, doped p-type polycrystalline Ge, and doped p-type polycrystalline SiGe.
Claim 19
Dependent Claim
23 words
A semiconductor device according to claim 1 , further comprising an insulating film between the semiconductor substrate and the complementary field effect transistor.
Claim 20
Dependent Claim
23 words
A semiconductor device according to claim 10 , further comprising an insulating film between the semiconductor substrate and the complementary field effect transistor.
Claim 21
Dependent Claim
159 words
A semiconductor device comprising: a semiconductor substrate; an n-channel field effect transistor formed on the semiconductor substrate; and a p-channel field effect transistor formed on the semiconductor substrate, the n-channel field effect transistor and the p-channel field effect transistor constituting a complementary field effect transistor, wherein a gate electrode of the n-channel field effect transistor and a gate electrode of the p-channel field effect transistor are made of a same material, and wherein one of the n-channel field effect transistor and the p-channel field effect transistor includes a first semiconductor layer in which at least a part of a channel region is formed, the other of the n-channel field effect transistor and the p-channel field effect transistor includes a second semiconductor layer in which at least a part of a channel region is formed and a third semiconductor layer as its under layer, and the first semiconductor layer and the third semiconductor layer are made of a same material.
Claim 22
Dependent Claim
159 words
A semiconductor device comprising: a semiconductor substrate; an n-channel field effect transistor formed on the semiconductor substrate; and a p-channel field effect transistor formed on the semiconductor substrate, the n-channel field effect transistor and the p-channel field effect transistor constituting a complementary field effect transistor, wherein a gate electrode of the n-channel field effect transistor and a gate electrode of the p-channel field effect transistor are made of a same material, and wherein one of the n-channel field effect transistor and the p-channel field effect transistor includes a first semiconductor layer in which at least a part of a channel region is formed, the other of the n-channel field effect transistor and the p-channel field effect transistor includes a second semiconductor layer in which at least a part of a channel region is formed and a third semiconductor layer as its under layer, and the first semiconductor layer and the third semiconductor layer are made of a same material.
Claim 23
Dependent Claim
23 words
A semiconductor device according to claim 19 , further comprising an insulating film between the semiconductor substrate and the complementary field effect transistor.
Claim 24
Dependent Claim
76 words
A semiconductor device according to claim 19 , wherein a work function of the material making the gate electrode is higher than an energy difference between a conduction band edge of a material making the channel region of the n-channel field effect transistor and a vacuum level, and is lower than an energy difference between a valence band edge of a material making the channel region of the p-channel field effect transistor and the vacuum level.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-01-14 | 2005-07-16 | 2006-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-01-14 | 2009-07-16 | 2010-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-01-14 | 2013-07-16 | 2014-01-15 | $7700.00 | Window Closed / Lapsed |