| 1. |
- Wernersson, Lars-Erik, et al.
(författare)
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Attractive potential around a buried metallic gate in a Schottky Collector Hot Electron Transistor
- 2002
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Ingår i: Institute of Physics Conference Series. - 0951-3248. ; 170, s. 81-85
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Tidskriftsartikel (refereegranskat)abstract
- We report on the formation of an attractive potential around buried metal wires in a novel design for the Hot Electron Transistor (HET). In this device, the doped base layer in the HET is replaced by an embedded metal grating, which is forward biased beyond flat band conditions in order to efficiently extract carriers from the emitter into the active region. These carriers are collected in a Schottky Collector contact. By tuning the gate and collector voltages, the potential profile around the wires can be repulsive as well as attractive. This is a key result for the realisation of a Biprism device.
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| 2. |
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| 3. |
- Lind, Erik, et al.
(författare)
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A resonant tunneling permeable base transistor with Al-free tunneling barriers
- 2002
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Ingår i: Device Research Conference (Cat. No.02TH8606). - 0780373170 ; , s. 155-156
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Konferensbidrag (refereegranskat)abstract
- Summary form only given. Resonant tunneling based devices are an intriguing set of devices with promising high speed, low power and high functionality capabilities. We have developed an technology to embed metallic features on the nm-scale inside a semiconductor. By combining such metallic features and heterostructures we have developed a new type of tunneling transistor, the so called Resonant Tunneling Permeable Base Transistor (RT-PBT), where a double barrier heterostructure is placed in close vicinity to a metal grating. A three step fabrication process is described
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| 4. |
- Lind, Erik, et al.
(författare)
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Realization of a resonant tunneling permeable base transistor with optimized overgrown GaAs interfaces
- 2002
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Ingår i: IEEE Transactions on Electron Devices. - 0018-9383. ; 49:6, s. 1066-1069
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Tidskriftsartikel (refereegranskat)abstract
- A resonant tunneling permeable base transistor has been realized experimentally by overgrowing a tungsten grating placed in direct vicinity to a double barrier heterostructure. In this way, we can directly modulate the tunneling current via an embedded gate. Since the quality of the overgrown interface is critical, special attention is paid to this issue, and the effect of different wet etchants prior to overgrowth is studied both by electrical measurements and by the use of an atomic force microscope. A clear dependence of the electrical properties and the crystal quality on the etchants used is found. This is a key result for the realization of our resonant tunneling device.
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| 5. |
- Lind, Erik, et al.
(författare)
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Resonant tunneling permeable base transistor based pulsed oscillator
- 2004
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Ingår i: Device Research Conference - Conference Digest, DRC. - 1548-3770. ; , s. 129-130
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Konferensbidrag (refereegranskat)abstract
- A technology was developed to embed nm-sized metallic features in close vicinity to semiconductor heterostructures, which allows a direct integration of resonant tunneling diodes (RTD) inside the channel of permeable base transistor. A AlGaAs/InGaAs based RTD was grown by molecular beam epitaxy (MBE), with peak current density either 70 or 120 kA/cm2. A fundamental oscillation frequency of 800 MHz was detected, with higher harmonics up to 2.6 GHz, using a spectrum analyzer. It was found that the oscillations could be quenched by applying a large (-1.5V) negative gate bias. The results indicate that a three terminal resonant tunneling transistor can be used to obtain pulsed operation of a resonant tunneling based oscillator.
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| 6. |
- Lind, Erik, et al.
(författare)
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Resonant Tunneling Permeable Base Transistor for RF applications
- 2003
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Ingår i: 2003 International Semiconductor Device Research Symposium (IEEE Cat. No.03EX741). - 0780381394 ; , s. 487-488
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Konferensbidrag (refereegranskat)abstract
- A technique is developed to embed tungsten inside semiconductors, with the possibility to combine the metallic elements and semiconductor heterostructure with nm-precision. This technique enables to fabricate a very high quality permeable base type of transistor. A resonant tunneling permeable base transistor, RT-PBT is fabricated by directly integrating a tungsten grating 30 nm above a pseudomorphic RTD. Double barrier heterostructure (AlGaAs/InGaAs) is grown by molecular beam epitaxy and the wafer is patterned by e-beam lithography to form the grating. Common collector current-voltage characteristics were measured at room temperature
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| 7. |
- Lind, Erik, et al.
(författare)
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Resonant tunneling permeable base transistors with high transconductance
- 2004
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Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 25:10, s. 678-680
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Tidskriftsartikel (refereegranskat)abstract
- A GaAs-based resonant tunneling permeable base transistor has been developed and evaluated at room temperature. The transistor is fabricated by overgrowing a tungsten gate placed next to an AlGaAs-GaAs-InGaAs resonant tunneling heterostructure. By changing the gate voltage, the effective conducting area of the tunnel diode can be modulated and the collector-emitter current thus controlled. Peak currents above 300 mA/mm and a maximum transconductance of 270 mS/mm have been obtained.
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| 8. |
- Lind, Erik, et al.
(författare)
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Stacking of heterostructures and metallic elements for a submicron resonant tunneling transistor
- 2002
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Ingår i: 7th International Conference on Nanometer-Scale Science and Technology and 21st European Conference on Surface Science.
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Konferensbidrag (refereegranskat)abstract
- We have successfully embedded a metal gate in-between two resonant tunneling double barrier heterostructures (RTD), thus realizing a three dimensional resonant tunneling transistor. The gate is placed 30 nm above and 100 below the two RTD's, respectively. The asymmetric gate allows for a unique control of the current-voltage characteristics, not only controlling the peak current but also the peak voltage. We have modeled the transistor with Cadence, a standard simulation package for circuit simulations, achieving good agreement with experimental data
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| 9. |
- Lind, Erik, et al.
(författare)
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Three-dimensional integrated resonant tunneling transistor with multiple peaks
- 2002
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 81:10, s. 1905-1907
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Tidskriftsartikel (refereegranskat)abstract
- A resonant tunneling transistor was manufactured by integrating a self-aligned metallic gate 30 nm above and 100 nm below resonant tunneling diodes. The Schottky depletion around the gate controls the current to a confined vertical channel with a conduction area in the range of 100x100 nm. Due to the three-dimensional asymmetric placement of the gate with respect to the tunneling diodes, modulation of both the peak voltage and peak current was achieved.
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| 10. |
- Lind, Erik, et al.
(författare)
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Tunneling spectroscopy of a quantum dot through a single impurity
- 2003
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 68:3, s. 4-4
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Tidskriftsartikel (refereegranskat)abstract
- A single impurity inside a resonant tunneling diode is used to perform tunneling spectroscopy on an adjacent electrostatically defined vertical quantum dot. This results in tunneling between two zero-dimensional systems, measured as a set of sharp peaks in the current-voltage spectrum for finite bias. Magnetic-field-dependent measurements show that the angular momentum of the tunneling electrons is conserved during the tunneling process. Both ground and excited states are probed. The effect of temperature is also investigated, exhibiting a peak broadening that is smaller than 1 kT.
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