← Back to Patent Explorer
US4556895A Expired / Lapsed US ⏱️ 0.0 years remaining

Field-effect transistor having a channel region of a Group III-V compound semiconductor and a Group IV semiconductor

Assignee: NEC Corp
•
Filing: 1983-04-26
•
Granted: 1985-12-03
•
Expires: 2003-04-26
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A field-effect semiconductor device having a channel region formed of two superimposed semiconductor layers, each layer being of a different type semiconductor. As between these two kinds of semiconductors, both the electron affinity and the sum of the electron affinity and the energy gap of one semiconductor is larger than the electron affinity and the sum of the electron affinity and the energy gap of the other semiconductor. This relationship is obtained by forming one of the semiconductor layers of Group III-V compound semiconductor and the other of Group IV semiconductor. The fabrication of the field-effect semiconductor device of this invention into monolithic integrated circuits is also disclosed.

Inventors

  • 👤 Keiichi Ohata

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 16:48
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/82; H10D30/00; H10D30/40; H10D30/47; H10D30/471; H10D30/473; H10D30/4732; H10D84/00; H10D84/01; H10D86/00; H10D86/01

Claims Analysis

Total Claims: 29
Claim 1
Independent Claim 127 words
A field-effect transistor comprising: a channel portion including a first semiconductor layer of an intrinsic semiconductor having a first electron affinity and a first energy gap and a second semiconductor layer of an intrinsic semiconductor having a second electron affinity and a second energy gap, said second semiconductor layer formed over said first semiconductor layer, said second electron affinity being smaller than said first electron affinity and the sum of said second electron affinity and said second energy gap being smaller than the sum of said first electron affinity and said first energy gap; a source region and a drain region in electrical contact with said channel portion and formed separated from each other; and a gate means for applying an electric field to said channel portion.
Claim 2
Dependent Claim 127 words
A field-effect transistor comprising: a channel portion including a first semiconductor layer of an intrinsic semiconductor having a first electron affinity and a first energy gap and a second semiconductor layer of an intrinsic semiconductor having a second electron affinity and a second energy gap, said second semiconductor layer formed over said first semiconductor layer, said second electron affinity being smaller than said first electron affinity and the sum of said second electron affinity and said second energy gap being smaller than the sum of said first electron affinity and said first energy gap; a source region and a drain region in electrical contact with said channel portion and formed separated from each other; and a gate means for applying an electric field to said channel portion.
Claim 3
Dependent Claim 29 words
A field-effect transistor according to claim 1, wherein said gate means includes an insulator film formed over said channel portion, and a gate electrode formed on said insulator film.
Claim 4
Dependent Claim 32 words
A field-effect transistor according to claim 2, wherein said first semiconductor layer is made of a Group III-V compound semiconductor, and wherein the second semiconductor is made of a Group IV semiconductor.
Claim 5
Dependent Claim 46 words
A field-effect transistor according to claim 3, wherein said Group III-V compound semiconductor is selected from the group consisting of InP, InGaAs, InGaAsP, InAs, and InAsP, whereas said semiconductor of an element from Group IV is selected from the group consisting of Ge, Si and SiGe.
Claim 6
Dependent Claim 22 words
A field-effect transistor according to claim 2, further comprising a third semiconductor layer interposed between said gate means and said channel portion.
Claim 7
Dependent Claim 82 words
A field-effect transistor according to claim 5, wherein said third semiconductor layer is directly formed on said second semiconductor layer on the side opposite to said first semiconductor layer, said third semiconductor layer having a third electron affinity and a third energy gap, said third electron affinity being smaller than said second electron affinity and the sum of said third electron affinity and said third energy gap being larger than the sum of said second electron affinity and said second energy gap.
Claim 8
Dependent Claim 16 words
A field-effect transistor according to claim 6, wherein said third semiconductor layer is made of GaAlAs.
Claim 9
Dependent Claim 113 words
A complementary semiconductor device comprising: first and second field-effect transistors each including a channel portion, which has a first semiconductor layer having no impurity for determining conductivity type and a second semiconductor layer formed over said first semiconductor layer, said second semiconductor layer having no impurity for determining conductivity type and having an electron affinity and the sum of the electron affinity and an energy gap smaller than those of said first semiconductor layer, a source region, a gate region and a drain region; circuit means for causing said first field-effect transistor to act as an N-channel element; and circuit means for causing said second field-effect transistor to act as a P-channel element.
Claim 10
Dependent Claim 113 words
A complementary semiconductor device comprising: first and second field-effect transistors each including a channel portion, which has a first semiconductor layer having no impurity for determining conductivity type and a second semiconductor layer formed over said first semiconductor layer, said second semiconductor layer having no impurity for determining conductivity type and having an electron affinity and the sum of the electron affinity and an energy gap smaller than those of said first semiconductor layer, a source region, a gate region and a drain region; circuit means for causing said first field-effect transistor to act as an N-channel element; and circuit means for causing said second field-effect transistor to act as a P-channel element.
Claim 11
Dependent Claim 27 words
A complementary semiconductor device according to claim 8, wherein the first semiconductor layers of said first and second field-effect transistors are constructed of a common semiconductor layer.
Claim 12
Dependent Claim 33 words
A complementary semiconductor device according to claim 9, wherein said first semiconductor layer is made of a Group III-V compound semiconductor, and wherein the other semiconductor is made of a Group IV semiconductor.
Claim 13
Dependent Claim 128 words
A field-effect transistor comprising: a channel portion including a first semiconductor layer of an intrinsic semiconductor having a first electron affinity and a first energy gap and a second semiconductor layer of an intrinsic semiconductor having a second electron affinity and a second energy gap, said second semiconductor layer being formed over said first semiconductor layer, said second electron affinity being larger than said first electron affinity and the sum of said second electron affinity and said second energy gap being larger than the sum of said first electron affinity and said first energy gap; a source region and a drain region in electrical contact with said channel portion and formed separated from each other; and a gate means for applying an electric field to said channel portion.
Claim 14
Dependent Claim 128 words
A field-effect transistor comprising: a channel portion including a first semiconductor layer of an intrinsic semiconductor having a first electron affinity and a first energy gap and a second semiconductor layer of an intrinsic semiconductor having a second electron affinity and a second energy gap, said second semiconductor layer being formed over said first semiconductor layer, said second electron affinity being larger than said first electron affinity and the sum of said second electron affinity and said second energy gap being larger than the sum of said first electron affinity and said first energy gap; a source region and a drain region in electrical contact with said channel portion and formed separated from each other; and a gate means for applying an electric field to said channel portion.
Claim 15
Dependent Claim 29 words
A field-effect transistor according to claim 11, wherein said gate means includes an insulator film formed over said channel portion, and a gate electrode formed on said insulator film.
Claim 16
Dependent Claim 32 words
A field-effect transistor according to claim 11, wherein said first semiconductor layer is made of a Group IV semiconductor, and wherein the second semiconductor is made of a Group III-V compound semiconductor.
Claim 17
Dependent Claim 46 words
A field-effect transistor according to claim 13, wherein said Group III-V compound semiconductor is selected from the group consisting of InP, InGaAs, InGaAsP, InAs, and InAsP, whereas said semiconductor of an element from Group IV is selected from the group consisting of Ge, Si and SiGe.
Claim 18
Dependent Claim 22 words
A field-effect transistor according to claim 12, further comprising a third semiconductor layer interposed between said gate means and said channel portion.
Claim 19
Dependent Claim 29 words
A field-effect transistor according to claim 12, wherein said third semiconductor layer is directly formed on said second semiconductor layer on the side opposite to said first semiconductor layer.
Claim 20
Dependent Claim 113 words
A complementary semiconductor device comprising: first and second field-effect transistors each including a channel portion, which has a first semiconductor layer having no impurity for determining conductivity type and a second semiconductor layer formed over said first semiconductor layer, said second semiconductor layer having no impurity for determining conductivity type and having an electron affinity and the sum of the electron affinity and an energy gap larger than those of said first semiconductor layer, a source region, a gate region and a drain region; circuit means for causing said first field-effect transistor to act as an N-channel element; and circuit means for causing said second field-effect transistor to act as a P-channel element.
Claim 21
Dependent Claim 113 words
A complementary semiconductor device comprising: first and second field-effect transistors each including a channel portion, which has a first semiconductor layer having no impurity for determining conductivity type and a second semiconductor layer formed over said first semiconductor layer, said second semiconductor layer having no impurity for determining conductivity type and having an electron affinity and the sum of the electron affinity and an energy gap larger than those of said first semiconductor layer, a source region, a gate region and a drain region; circuit means for causing said first field-effect transistor to act as an N-channel element; and circuit means for causing said second field-effect transistor to act as a P-channel element.
Claim 22
Dependent Claim 27 words
A complementary semiconductor device according to claim 17, wherein the first semiconductor layers of said first and second field-effect transistors are constructed of a common semiconductor layer.
Claim 23
Dependent Claim 35 words
A complementary semiconductor device according to claim 18, wherein one of said first semiconductor layer is madee of a Group IV semiconductor, and wherein the other semiconductor is made of a Group III-V compound semiconductor.
Claim 24
Dependent Claim 35 words
A field-effect transistor as claimed in claim 1, further comprising a third semiconductor layer interposed between said gate means and said channel portion, said gate means comprising metal electrode formed on said third semiconductor layer.
Claim 25
Dependent Claim 24 words
A field-effect transistor as claimed in claim 20, wherein said metal electrode is selected from a group consisting of Al, Ti, Pt and W.
Claim 26
Dependent Claim 35 words
A field-effect transistor as claimed in claim 11, further comprising a third semiconductor layer interposed between said gate means and said channel portion, said gate means comprising metal electrode formed on said third semiconductor layer.
Claim 27
Dependent Claim 24 words
A field-effect transistor as claimed in claim 22, wherein said metal electrode is selected from a group consisting of Al, Ti, Pt and W.
Claim 28
Dependent Claim 48 words
A field-effect transistor as claimed in claim 1, further comprising a third semiconductor layer directly formed on said first semiconductor layer on the side opposite to said second semiconductor layer, said third semiconductor layer having an electron affinity smaller than the electron affinity of said first semiconductor layer.
Claim 29
Dependent Claim 17 words
A field-effect transistor as claimed in claim 24, wherein said third semiconductor layer is made of GaAsSb.

References Cited (Backward Citations)

US3283221A Cited
US3263095A Cited
US3708731A Cited
US4163237A Cited
JPS55117281A Cited
US4424525A Cited
JPS5861675A Cited
JPS58102561A Cited
JPS58130574A Cited
JPS58130572A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-12-02 1989-06-03 1989-12-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-12-02 1993-06-03 1993-12-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-12-02 1997-06-03 1997-12-03 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag