| 1. |
- 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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| 2. |
- 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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| 3. |
- 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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| 4. |
- 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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| 5. |
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| 6. |
- Wernersson, Lars-Erik, et al.
(författare)
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A combined chemical vapor deposition and rapid thermal diffusion process for SiGe Esaki diodes by ultra-shallow junction formation
- 2005
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Ingår i: IEEE Transactions on Nanotechnology. - 1536-125X. ; 4:5, s. 594-598
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Tidskriftsartikel (refereegranskat)abstract
- SiGe Esaki diodes have been realized by rapid thermal diffusion of phosphorous into an SiGe layer grown by ultra-high-vacuum chemical-vapor-deposition on an Si p(+)-substrate for the first time. The phosphorous-doped SiGe forms the n(+)-electrode, while heavily boron-doped Si0.74Ge0.26 and Si substrate is used for the p(+) electrode. The diodes show a peak current density of 0.18 kA/cm(2), a current peak-to-valley ratio of 2.6 at room temperature, and they exhibit only a weak temperature dependence. Cross-sectional transmission microscopy showed a good crystalline quality of the strained Si0.74Ge0.26 layer even after the diffusion step at 900 degrees C.
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| 7. |
- 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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| 8. |
- Wernersson, Lars-Erik, et al.
(författare)
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InAs epitaxial lateral overgrowth of W masks
- 2005
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 280:1-2, s. 81-86
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Tidskriftsartikel (refereegranskat)abstract
- The conditions for successful epitaxial lateral overgrowth of W patterns by InAs using low-pressure metalorganic vapour phase epitaxy were studied. The substrates used were InAs (0 0 1) wafers and the range of growth temperatures between 500 and 600 degrees C. The selective growth was investigated as a function of the V/III-ratio on W-ring test structures and wires oriented in different directions. 100-nm-wide wires, oriented in 30 degrees off from the [1 1 0]-direction, were completely covered with InAs without any void formation and the surface was planarized after deposition of 3 50 nm at the V/III-ratio of 14. Wires oriented along the [1 1 0]-direction were found to effectively block the lateral overgrowth by the formation of mesa ridges limited by {110} and {111} A-planes for V/III-ratios between 14 and 56. All other grating directions showed limited lateral growth. This observed orientation dependence is in general agreement with the overgrowth of GaAs, but shows differences compared to InP.
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| 9. |
- Wernersson, Lars-Erik, et al.
(författare)
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Metalorganic vapor phase epitaxy-grown GaP/GaAs/GaP and GaAsP/GaAs/GaAsP n-type resonant tunnelling diodes
- 2002
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 80:10, s. 1841-1843
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Tidskriftsartikel (refereegranskat)abstract
- We have studied GaP/GaAs/GaP and GaAsxP1-x/GaAs/GaAsxP1-x double-barrier resonant tunnelling diodes grown by metalorganic vapor phase epitaxy. We find that GaP tensile strained barriers in GaP/GaAs/GaP diodes may be grown with a barrier thickness below the critical thickness of about 12 monolayers. However, a corrugation of the strained barrier is observed by transmission electron microscopy. This variation may explain the low peak-to-valley ratio of the diodes (about 2). In contrast, GaAsxP1-x/GaAs/GaAsxP1-x resonant tunnelling diodes have been grown with a homogeneous thickness of the barriers, consequently showing a substantially improved electrical performance compared to the GaP diodes with peak-to-valley ratios >5.
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| 10. |
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