US6492669B2
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Semiconductor device with schottky electrode having high schottky barrier
Assignee: NEC Corp
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Filing: 2001-06-28
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Granted: 2002-12-10
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Expires: 2021-06-28
Abstract
Abstract A carrier travel layer is formed on the substrate of a semiconductor device with a buffer layer interposed, and a spacer layer and carrier supply layer are then formed on this carrier travel layer. On the carrier supply layer are provided a source electrode and a drain electrode, and a gate electrode is provided on an interposed Schottky layer. The carrier supply layer is composed of AlGaN and has tensile strain. The Schottky layer is composed of InGaN and has compressive strain. A negative piezoelectric charge is induced on the carrier supply layer side of the Schottky layer, and a positive piezoelectric charge is induced on the opposite side of the Schottky layer, whereby a sufficient Schottky barrier height is obtained and leakage current is suppressed.
Inventors
- 👤 Tatsuo Nakayama
- 👤 Yuji Ando
- 👤 Hironobu Miyamoto
- 👤 Kazuaki Kunihiro
- 👤 Yuji Takahashi
- 👤 Kensuke Kasahara
- 👤 Nobuyuki Hayama
- 👤 Yasuo Ohno
- 👤 Kouji Matsunaga
- 👤 Masaaki Kuzuhara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:24
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/015; H10D30/40; H10D30/47; H10D30/471; H10D30/473; H10D30/4732; H10D30/60; H10D30/67; H10D30/6729; H10D30/6737; H10D30/6738; H10D30/674; H10D30/675; H10D62/00; H10D62/80; H10D62/85; H10D64/00; H10D64/01; H10D64/012; H10D64/0124; H10D64/0125; H10D64/60; H10D64/64; H10D62/8503
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
81 words
A semiconductor device comprising: a first electron barrier layer; a second electron barrier layer formed on said first electron barrier layer either directly or on an interposed spacer layer and in which a negative piezoelectric charge is induced on said first electron barrier layer side and a positive piezoelectric charge is induced on the opposite side; and a Schottky electrode of sufficient height formed on the side of said second electron barrier layer in which said positive piezoelectric charged is induced.
Claim 2
Dependent Claim
81 words
A semiconductor device comprising: a first electron barrier layer; a second electron barrier layer formed on said first electron barrier layer either directly or on an interposed spacer layer and in which a negative piezoelectric charge is induced on said first electron barrier layer side and a positive piezoelectric charge is induced on the opposite side; and a Schottky electrode of sufficient height formed on the side of said second electron barrier layer in which said positive piezoelectric charged is induced.
Claim 3
Dependent Claim
27 words
A semiconductor device according to claim 1 , wherein said first electron barrier layer and said second electron barrier layer are both composed of III-nitride semiconductor materials.
Claim 4
Dependent Claim
26 words
A semiconductor device according to claim 1 , wherein said Schottky electrode is a gate electrode, and further comprising a source electrode and a drain electrode.
Claim 5
Dependent Claim
34 words
A semiconductor device according to claim 3 , wherein said source electrode and said drain electrode are formed in contact with a III-nitride semiconductor layer that has no strain or that has tensile strain.
Claim 6
Dependent Claim
30 words
The new semiconductor device according to claim 1 , wherein said second electron barrier layer is formed from a material having a lattice constant larger than a thick base layer.
Claim 7
Dependent Claim
43 words
The semiconductor device according to claim 1 , further comprising a carrier travel layer formed on a substrate with a buffer layer interposed, wherein said lattice constant of said second electron barrier layer is higher than a constant of said carrier travel layer.
Claim 8
Dependent Claim
23 words
A semiconductor device according to claim 1 , further comprising: a semiconductor layer with a compressive strain formed directly beneath said Schottky electrode.
Claim 9
Dependent Claim
45 words
A semiconductor device according to claim 1 , wherein a negative piezoelectric charge is induced in said second electron barrier layer side of said first electron barrier layer and a postive piezoelectric charge is induced on the opposite side of said first electron barrier layer.
Claim 10
Dependent Claim
27 words
A semiconductor device according to claim 8 , wherein said first electron barrier layer and said second electron barrier layer are both composed of III-nitride semiconductor materials.
Claim 11
Dependent Claim
109 words
A semiconductor device comprising: a base layer that is a wurtzite III-nitride semiconductor layer in which the (0001) plane is the principal plane; a first electron barrier layer that is formed on said base layer and that is a wurtzite III-nitride semiconductor layer in which the (0001) plane is the principal plane; a second electron barrier layer formed on said first electron barrier layer either directory or on an interposed spacer layer, said second electron barrier layer being a wurtzite III-nitride semiconductor layer in which the (0001) plane is the principal plane and having compressive strain; and a Schottky electrode that is formed on said second electron barrier layer.
Claim 12
Dependent Claim
109 words
A semiconductor device comprising: a base layer that is a wurtzite III-nitride semiconductor layer in which the (0001) plane is the principal plane; a first electron barrier layer that is formed on said base layer and that is a wurtzite III-nitride semiconductor layer in which the (0001) plane is the principal plane; a second electron barrier layer formed on said first electron barrier layer either directory or on an interposed spacer layer, said second electron barrier layer being a wurtzite III-nitride semiconductor layer in which the (0001) plane is the principal plane and having compressive strain; and a Schottky electrode that is formed on said second electron barrier layer.
Claim 13
Dependent Claim
17 words
A semiconductor device according to claim 10 , wherein said first electron barrier layer has tensile strain.
Claim 14
Dependent Claim
26 words
A semiconductor device according to claim 10 , wherein said Schottky electrode is a gate electrode and further comprising a source electrode and a drain electrode.
Claim 15
Dependent Claim
34 words
A semiconductor device according to claim 12 , wherein said source electrode and said drain electrode are formed in contact with a III-nitride semiconductor layer that has no strain or that has tensile strain.
Claim 16
Dependent Claim
147 words
A semiconductor device comprising: a base layer that is a wurtizte III-nitride semiconductor layer in which the (001) plane is the principal plane; a first electron barrier layer that is formed on said base layer that is a wurtzite III-nitride semiconductor layer in which the (001) plane is the principal plane; a second electron barrier layer that is formed on said first electron barrier layer either directly or on an interposed spacer layer, said second electron barrier layer being a wurtzite III-nitride semiconductor layer in which the (001) plane is the principal plane, and having a greater average lattice constant than that of said base layer, where the average lattice constant is defined as the average value of the lattice constant in the horizontal plane that is perpendicular to the direction of film thickness; and a Schottky electrode that is formed on said second electron barrier layer.
Claim 17
Dependent Claim
147 words
A semiconductor device comprising: a base layer that is a wurtizte III-nitride semiconductor layer in which the (001) plane is the principal plane; a first electron barrier layer that is formed on said base layer that is a wurtzite III-nitride semiconductor layer in which the (001) plane is the principal plane; a second electron barrier layer that is formed on said first electron barrier layer either directly or on an interposed spacer layer, said second electron barrier layer being a wurtzite III-nitride semiconductor layer in which the (001) plane is the principal plane, and having a greater average lattice constant than that of said base layer, where the average lattice constant is defined as the average value of the lattice constant in the horizontal plane that is perpendicular to the direction of film thickness; and a Schottky electrode that is formed on said second electron barrier layer.
Claim 18
Dependent Claim
33 words
A semiconductor device according to claim 14 , wherein the average lattice constant of said first electron barrier layer is equal to or smaller than the average lattice constant of said base layer.
Claim 19
Dependent Claim
53 words
A semiconductor device according to claim 15 , wherein: said base layer is composed of Al α Ga (1−α) N; (0≦α≦1); said first electron barrier layer is composed of Al β Ga (1−β) N; (α≦β≦1); and said second electron barrier layer is composed of In x Ga y Al (1−x−y) N; (0<x≦1, 0≦y<1).
Claim 20
Dependent Claim
50 words
A semiconductor device according to claim 15 , wherein: said base layer is composed of Al α Ga (1−α) N; (0<α≦1); said first electron barrier layer is composed of Al β Ga (1−β) N; (α≦β≦1); and said second electron barrier layer is composed of Al γ Ga (1−γ) N; (0≦γ≦α).
Claim 21
Dependent Claim
26 words
A semiconductor device according to claim 14 , wherein said Schottky electrode is a gate electrode and further comprising a source electrode and a drain electrode.
Claim 22
Dependent Claim
34 words
A semiconductor device according to claim 18 , wherein said source electrode and said drain electrode are formed in contact with a III-nitride semiconductor layer that has no strain or that has tensile strain.
Claim 23
Dependent Claim
78 words
A semiconductor device comprising: a plurality of wurtzite III-nitride semiconductor layers in which the (0001) plane is the principal plane including a first layer composed of GaN and a second layer composed of Al x Ga (1−x) N; (0<x≦1); a gate electrode that is formed on said III-nitride semiconductor layers so as to contact said first layer; and a source electrode and a drain electrode formed on said III-nitride semiconductor layers so as to contact said second layer.
Claim 24
Dependent Claim
78 words
A semiconductor device comprising: a plurality of wurtzite III-nitride semiconductor layers in which the (0001) plane is the principal plane including a first layer composed of GaN and a second layer composed of Al x Ga (1−x) N; (0<x≦1); a gate electrode that is formed on said III-nitride semiconductor layers so as to contact said first layer; and a source electrode and a drain electrode formed on said III-nitride semiconductor layers so as to contact said second layer.
References Cited (Backward Citations)
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