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Patent US5324959A successfully refreshed from Google Patents.
US5324959A
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Semiconductor optical device having a heterointerface therein
Assignee: Hitachi Ltd
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Filing: 1992-05-14
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Granted: 1994-06-28
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Expires: 2012-05-14
Abstract
Abstract A semiconductor device includes a region in which carriers are transferred in the lamination direction of a multiple quantum well, such as a multiple quantum well multiplication layer of a superlattice APD. A superlattice structure with a varying well width is introduced to a hetero-interface present in the transfer region, thereby preventing pile-up of the carriers.
Inventors
- 👤 Hitoshi Nakamura
- 👤 Shoichi Hanatani
- 👤 Chiaki Notsu
- 👤 Tsukuru Ohtoshi
- 👤 Koji Ishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:40
CPC Classifications
B; B82; B82Y; B82Y20/00; H; H10; H10F; H10F77/00; H10F77/10; H10F77/14; H10F77/146
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
146 words
A semiconductor device including: a first semiconductor layer; a second semiconductor layer disposed on the first semiconductor layer, said second semiconductor layer having a first superlattice structure comprising first semiconductor regions having a first energy bandgap and second semiconductor regions having a second energy bandgap greater than the first energy bandgap, the first semiconductor regions and the second semiconductor regions being alternately disposed; and a third semiconductor layer disposed on the second semiconductor layer, wherein the second semiconductor layer further comprises second superlattice structures each disposed between the first and second semiconductor regions, each of the second superlattice structures comprising third semiconductor regions having a third energy bandgap and fourth semiconductor regions having a fourth energy bandgap greater than the third energy bandgap, the third semiconductor regions and the fourth semiconductor regions being alternately disposed so that each of the second superlattice structures forms a miniband.
Claim 2
Dependent Claim
146 words
A semiconductor device including: a first semiconductor layer; a second semiconductor layer disposed on the first semiconductor layer, said second semiconductor layer having a first superlattice structure comprising first semiconductor regions having a first energy bandgap and second semiconductor regions having a second energy bandgap greater than the first energy bandgap, the first semiconductor regions and the second semiconductor regions being alternately disposed; and a third semiconductor layer disposed on the second semiconductor layer, wherein the second semiconductor layer further comprises second superlattice structures each disposed between the first and second semiconductor regions, each of the second superlattice structures comprising third semiconductor regions having a third energy bandgap and fourth semiconductor regions having a fourth energy bandgap greater than the third energy bandgap, the third semiconductor regions and the fourth semiconductor regions being alternately disposed so that each of the second superlattice structures forms a miniband.
Claim 3
Dependent Claim
171 words
A semiconductor device including: a first semiconductor layer; a second semiconductor layer disposed on the first semiconductor layer, said second semiconductor layer having a first superlattice structure comprising first semiconductor regions having a first energy bandgap and second semiconductor regions having a second energy bandgap greater than the first energy bandgap, the first semiconductor regions and the second semiconductor regions being alternately disposed; and a third semiconductor layer disposed on the second semiconductor layer, wherein the second semiconductor layer further comprises second superlattice structures each disposed between the first and second semiconductor regions, each of the second superlattice structures comprising third semiconductor regions having a third energy bandgap and fourth semiconductor regions having a fourth energy bandgap greater than the third energy bandgap, the third semiconductor regions and the fourth semiconductor regions being alternately disposed so that each of the second superlattice structures forms a miniband; and wherein the first energy bandgap is equal to the third energy bandgap and the second energy bandgap is equal to the fourth energy bandgap.
Claim 4
Dependent Claim
171 words
A semiconductor device including: a first semiconductor layer; a second semiconductor layer disposed on the first semiconductor layer, said second semiconductor layer having a first superlattice structure comprising first semiconductor regions having a first energy bandgap and second semiconductor regions having a second energy bandgap greater than the first energy bandgap, the first semiconductor regions and the second semiconductor regions being alternately disposed; and a third semiconductor layer disposed on the second semiconductor layer, wherein the second semiconductor layer further comprises second superlattice structures each disposed between the first and second semiconductor regions, each of the second superlattice structures comprising third semiconductor regions having a third energy bandgap and fourth semiconductor regions having a fourth energy bandgap greater than the third energy bandgap, the third semiconductor regions and the fourth semiconductor regions being alternately disposed so that each of the second superlattice structures forms a miniband; and wherein the first energy bandgap is equal to the third energy bandgap and the second energy bandgap is equal to the fourth energy bandgap.
Claim 5
Dependent Claim
193 words
A semiconductor device including: a first semiconductor layer; a second semiconductor layer disposed on the first semiconductor layer, said second semiconductor layer having a first superlattice structure comprising first semiconductor regions having a first energy bandgap and second semiconductor regions having a second energy bandgap greater than the first energy bandgap, the first semiconductor regions and the second semiconductor regions being alternately disposed; and a third semiconductor layer disposed on the second semiconductor layer, wherein the second semiconductor layer further comprises second superlattice structures each disposed between the first and second semiconductor regions, each of the second superlattice structures comprising third semiconductor regions having a third energy bandgap and fourth semiconductor regions having a fourth energy bandgap greater than the third energy bandgap, the third semiconductor regions and the fourth semiconductor regions being alternately disposed so that each of the second superlattice structures forms a miniband; and wherein the first semiconductor layer comprises a layer of InAlAs, each of the first and third semiconductor regions comprises a layer of InGaAs, each of the second and fourth semiconductor regions comprises a layer of InAlAs and the third semiconductor layer comprises a layer of InAlAs.
Claim 6
Dependent Claim
193 words
A semiconductor device including: a first semiconductor layer; a second semiconductor layer disposed on the first semiconductor layer, said second semiconductor layer having a first superlattice structure comprising first semiconductor regions having a first energy bandgap and second semiconductor regions having a second energy bandgap greater than the first energy bandgap, the first semiconductor regions and the second semiconductor regions being alternately disposed; and a third semiconductor layer disposed on the second semiconductor layer, wherein the second semiconductor layer further comprises second superlattice structures each disposed between the first and second semiconductor regions, each of the second superlattice structures comprising third semiconductor regions having a third energy bandgap and fourth semiconductor regions having a fourth energy bandgap greater than the third energy bandgap, the third semiconductor regions and the fourth semiconductor regions being alternately disposed so that each of the second superlattice structures forms a miniband; and wherein the first semiconductor layer comprises a layer of InAlAs, each of the first and third semiconductor regions comprises a layer of InGaAs, each of the second and fourth semiconductor regions comprises a layer of InAlAs and the third semiconductor layer comprises a layer of InAlAs.
Claim 7
Dependent Claim
100 words
A photodiode including: a buffer layer; a superlattice multiplication layer disposed on the buffer layer, comprising first well layers and first barrier layers which are alternately disposed; and an absorption layer disposed on the superlattice multiplication layer, wherein the superlattice multiplication layer further comprises superlattice structures disposed between the first well layers and the first barrier layers, respectively, each of the superlattice structures comprising second barrier layers and second well layers which are alternately disposed so that each of the superlattice structures forms a miniband, thickness of the second well layers in each superlattice structure decreasing toward the buffer layer.
Claim 8
Dependent Claim
100 words
A photodiode including: a buffer layer; a superlattice multiplication layer disposed on the buffer layer, comprising first well layers and first barrier layers which are alternately disposed; and an absorption layer disposed on the superlattice multiplication layer, wherein the superlattice multiplication layer further comprises superlattice structures disposed between the first well layers and the first barrier layers, respectively, each of the superlattice structures comprising second barrier layers and second well layers which are alternately disposed so that each of the superlattice structures forms a miniband, thickness of the second well layers in each superlattice structure decreasing toward the buffer layer.
Claim 9
Dependent Claim
22 words
The photodiode according to claim 4, further including a field adjusting layer disposed between the superlattice multiplication layer and the absorption layer.
Claim 10
Dependent Claim
38 words
The photodiode according to claim 4, wherein the second barrier layers have the same material as that of the first barrier layers and the second well layers have the same material as that of the first well layers.
Claim 11
Dependent Claim
50 words
The photodiode according to claim 4, wherein the buffer layer comprises a layer of InAlAs, each of the first and second well layers comprises a layer of InGaAs, each of the first and second barrier layers comprises a layer of InAlAs and the absorption layer comprises a layer of InGaAs.
Claim 12
Dependent Claim
115 words
An optical modulator including: a first cladding layer; a multiple quantum well optical waveguide layer disposed on the first cladding layer, comprising first well layers and first barrier layers which are alternately disposed; and a second cladding layer disposed on the multiple quantum well optical waveguide layer, wherein the multiple quantum well optical waveguide layer further comprises superlattice structures disposed between the first well layers and the first barrier layers, respectively, each of the superlattice structures comprising second barrier layers and second well layers which are alternately disposed so that each of the superlattice structures forms a miniband, thickness of the second well layers decreasing gradually in each superlattice structure toward the first cladding layer.
Claim 13
Dependent Claim
115 words
An optical modulator including: a first cladding layer; a multiple quantum well optical waveguide layer disposed on the first cladding layer, comprising first well layers and first barrier layers which are alternately disposed; and a second cladding layer disposed on the multiple quantum well optical waveguide layer, wherein the multiple quantum well optical waveguide layer further comprises superlattice structures disposed between the first well layers and the first barrier layers, respectively, each of the superlattice structures comprising second barrier layers and second well layers which are alternately disposed so that each of the superlattice structures forms a miniband, thickness of the second well layers decreasing gradually in each superlattice structure toward the first cladding layer.
Claim 14
Dependent Claim
39 words
The optical modulator according to claim 8, wherein the second barrier layers have the same material as that of the first barrier layers and the second well layers have the same material as that of the first well layers.
Claim 15
Dependent Claim
35 words
The optical modulator according to claim 8, wherein each of the first and second well layers comprises a layer of InGaAs and each of the first and second barrier layers comprises a layer of InAlAs.
Claim 16
Dependent Claim
38 words
The photodiode according to claim 5, wherein the second barrier layers have the same material as that of the first barrier layers and the second well layers have the same material as that of the first well layers.
Claim 17
Dependent Claim
50 words
The photodiode according to claim 5, wherein the buffer layer comprises a layer of InAlAs, each of the first and second well layers comprises a layer of InGaAs, each of the first and second barrier layers comprises a layer of InAlAs and the absorption layer comprises a layer of InGaAs.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
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