| 1. |
- Astromskas, Gvidas, et al.
(författare)
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Temperature dependence of GaSb overgrowth of tungsten on GaSb (001) substrates using MOVPE
- 2008
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Ingår i: 20th International Conference on Indium Phosphide and Related Materials, 2008. IPRM 2008. - 1092-8669. ; , s. 354-356
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Konferensbidrag (refereegranskat)abstract
- We demonstrate GaSb overgrowth over tungsten patterns and that selective area epitaxy is achievable in the W/GaSb system. By controlling the facet growth at low temperatures, it is possible to embed a metal grating in a thin layer.
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| 2. |
- Astromskas, Gvidas, et al.
(författare)
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Thin InAs membranes and GaSb buffer layers on GaAs(001) substrates
- 2012
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Ingår i: Journal of Vacuum Science and Technology B. - : American Vacuum Society. - 1520-8567. ; 30:5
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Tidskriftsartikel (refereegranskat)abstract
- Thin InAs layers and membranes are fabricated on GaAs substrates using GaSb buffer layers grown by MOVPE. The quality of the GaSb buffer layers is optimized and epitaxial InAs layers are grown on GaSb layers of various thickness. The best GaSb buffer layers are obtained for a nucleation temperature of 450 degrees C and a subsequent growth temperature of 570 degrees C with a V/III ratio of 3, as confirmed by both the structural (high-resolution XRD, AFM) and electrical (Hall) measurements. Furthermore, a clear relationship between the structural quality of the GaSb and InAs layers is established. Finally, free-standing InAs structures are fabricated where Hall measurements reveal a mobility that depends on the film thickness.
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| 3. |
- Egard, Mikael, et al.
(författare)
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60 GHz Wavelet Generator for Impulse Radio Applications
- 2009
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Ingår i: European Microwave Conference, 2009. EuMC 2009. - 9781424447480 ; , s. 1908-1911, s. 234-237
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Konferensbidrag (refereegranskat)abstract
- A wavelet generator producing 100 ps short pulses at 60 GHz is presented. The wavelet generator consists of a gated tunnel diode (GTD) integrated in parallel with an inductor. This forms a negative differential conductance (NDC) oscillator with the ability to switch the NDC property on and off, which makes it possible to generate short pulses. In the experiments described, the wavelet generator drives a 50 Omega load and delivers 206 mV(pp) when generating 97 ps short pulses at 60 GHz. It Is demonstrated that it is possible to generate pulses of different length and phase. An explanation of the almost instantaneously startup and decay lapse of the oscillator, including generation of signals with opposite phase, is presented. This novel circuit may find use in ultra-wideband impulse radio communication.
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