EP0696065A2
Expired / Lapsed
EP
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Conduction control device
Assignee: Hitachi Europe Ltd
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Filing: 1995-06-29
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Granted: —
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Expires: 2015-06-29
Abstract
Abstract A conduction control device, for example a single electron transistor consists of a source 1, a drain 2 and a charge-receiving island 3 separated from the source and drain by respective tunnel barrier junctions TJ1, TJ2. The device is constructed on the nanometre scale, and the charge on the island 3 is limited by the Coulomb blockade effect to a small discrete number of electrons. A gate electrode 4 overlies the island 3. In order to provide a high gate/drain gain, a voltage drop region 15 is connected in series between the tunnel barrier junction TJ2 and the drain 2 so as to increase the effective Coulomb gap voltage V c .
Inventors
- 👤 Kazuo Nakazato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 13:20
CPC Classifications
B; B82; B82Y; B82Y10/00; H; H10; H10D; H10D30/00; H10D30/40; H10D30/402
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
136 words
A conduction control device including a source region (1), a charge-receiving region (3) for charge from the source region, a drain region (2) for charge from the charge-receiving region, first and second barrier regions (13, 14) between the charge-receiving region and the source and drain regions respectively, the charge in the charge-receiving region being limited by Coulomb Blockade to a given energy level relative to a base energy level (16), means for raising the energy of the source region above the base level for causing charge to tunnel through the first barrier into the charge-receiving region, and characterised by means (15) for lowering the energy of the drain region (2) below the base level (16) so as to promote charge in the charge-receiving region (3) to tunnel through the second barrier (14) to the drain region.
Claim 2
Dependent Claim
38 words
A device according to claim 1 wherein the means for lowering the energy of the drain region includes means (15) for producing a voltage drop, connected in series between the second barrier (14) and the drain region (2).
Claim 3
Dependent Claim
79 words
A device according to claim 1 or 2 including a substrate (11), means defining a channel (12) with a relatively high conductivity, means (13, 14) defining the first and second barriers spaced apart along the channel whereby relatively conductive regions of the channel define said source (1), charge-receiving (3) and drain regions (2), and said voltage drop region comprises means for defining a relatively high impedance region (15) in the channel between the second barrier and the drain region.
Claim 4
Dependent Claim
24 words
A device according to claim 3 wherein the first and second barrier regions comprise regions (13, 14) of reduced width in the channel (12).
Claim 5
Dependent Claim
30 words
A device according to claim 3 or 4 including a layer structure on the substrate for producing an essentially two dimensional electron gas along the length of the channel (12).
Claim 6
Dependent Claim
31 words
A device according to claim 5 wherein the voltage drop region (15) comprises a region of the channel doped to produce a relatively high impedance depletion region in the electron gas.
Claim 7
Dependent Claim
25 words
A device according to claim 5 wherein the voltage drop region (15) has been defined by partial removal of a portion of said layer structure.
Claim 8
Dependent Claim
26 words
A device according to claim 3, 4 or 5 wherein the voltage drop region (15) is defined by a region of reduced width in the channel.
Claim 9
Dependent Claim
26 words
A device according to claim 8 wherein the voltage drop region includes a plurality of regions (TJ3...TJ6) of reduced width along the length of the channel.
Claim 10
Dependent Claim
28 words
A device according to claim 8 or 9 including control electrode means (17, 18) associated with the or each channel width restriction for controlling the barrier height thereof.
Claim 11
Independent Claim
18 words
A device according to any preceding claim including gate electrode means (14) capacitively coupled to the charging region.
Claim 12
Independent Claim
32 words
A device according to any preceding claim including first and second control electrode means (17, 18) associated with the first and second barriers (13, 14) respectively for controlling the barrier heights thereof.
Claim 13
Dependent Claim
60 words
A device according to claim 3 wherein the channel (12) includes a region (19) containing a multiple tunnel junction structure that extends between the source region (1) and the drain region (2), said structure comprising a plurality of spaced tunnel junctions with a plurality of charge receiving islands therebetween, and a control electrode (20) overlying the multiple tunnel junction structure.
Claim 14
Dependent Claim
39 words
A device according to claim 13 wherein the multiple tunnel junction structure defines a barrier region (21) between the source region and said control electrode, and a voltage drop region (22) between the control electrode and the drain region.
Claim 15
Independent Claim
14 words
A device according to any preceding claim and comprising a single electron transistor (10).
Claim 16
Independent Claim
33 words
A device according to any preceding claim having its source-drain path connected in series with a load impedance (R) between rail voltage sources (V cc ), whereby to provide a logic circuit element.
References Cited (Backward Citations)
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