| 1. |
- Iniguez-de-la-Torre, I., et al.
(författare)
-
Monte Carlo studies of the intrinsic time-domain response of nanoscale three-branch junctions
- 2012
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 111:8
-
Tidskriftsartikel (refereegranskat)abstract
- We present a Monte Carlo time-domain study of nanostructured ballistic three-branch junctions (TBJs) excited by both step-function and Gaussian picosecond transients. Our TBJs were based on InGaAs 2-dimensional electron gas heterostructures and their geometry followed exactly the earlier experimental studies. Time-resolved, picosecond transients of both the central branch potential and the between-the-arms current demonstrate that the bandwidth of the intrinsic TBJ response reaches the THz frequency range, being mainly limited by the large-signal, intervalley scattering, when the carrier transport regime changes from ballistic to diffusive.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
-
DC and RF cryogenic behaviour of InAs/AlSb HEMTs
- 2010
-
Ingår i: International Conference on Indium Phosphide and Related Materials. Proceedings. 22nd International Conference on Indium Phosphide and Related Materials, IPRM 2010; Kagawa; 31 May 2010 through 4 June 2010. - 1092-8669. - 9781424459209 ; , s. 321-324
-
Konferensbidrag (refereegranskat)abstract
- DC and RF properties are reported for InAs/AlSb HEMTs operating under cryogenic conditions (6 K) for a drain source bias up to 0.3 V. Compared to room temperature (300 K), a large improvement in device properties was observed: lower R on , lower g ds , a more distinct knee in the I ds (V ds ) characteristics, increased f T and a reduction of the gate leakage current of more than two orders of magnitude. This makes InAs/AlSb HEMT technology of large interest in cryogenic low-noise amplifier designs with high constraints on power dissipation.
|
|
| 5. |
- Rodilla, H., et al.
(författare)
-
Dynamic Monte Carlo study of isolated-gate InAs/AlSb HEMTs
- 2011
-
Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 1361-6641 .- 0268-1242. ; 26:2
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, by means of Monte Carlo simulations, the static and dynamic behavior of isolated-gate InAs/AlSb high electron mobility transistors (Sb-HEMTs) has been studied and compared with experimental results. The influence of the existence of a native oxide under the gate, the value of the surface charges in the gate recess and the possible variation of electron sheet carrier density, n(s), have been studied. A decrease in the gate-source capacitance, transconductance and intrinsic cutoff frequency is observed because of the presence of the native oxide, while changes in the value of the surface charges in the recess only introduce a threshold voltage shift. The increase of n(s) shifts the maximum of the transconductance and intrinsic cutoff frequency to higher values of drain current and improves the agreement with the experimental results.
|
|
| 6. |
- Rodilla, H., et al.
(författare)
-
Isolated-gate InAs/AlSb HEMTs: A Monte Carlo study
- 2010
-
Ingår i: International Conference on Indium Phosphide and Related Materials. Proceedings. 22nd International Conference on Indium Phosphide and Related Materials, IPRM 2010; Kagawa; 31 May 2010 through 4 June 2010. - 1092-8669. - 9781424459209 ; , s. 333-336
-
Konferensbidrag (refereegranskat)abstract
- In this work we present a Monte Carlo study of the influence of the presence of a native oxide which isolates the gate in InAs/AlSb high electron mobility transistors (HEMTs) on their dc and ac performance. A good agreement between simulations and experimental results of I-V curves and small signal equivalent circuit parameters has been found for low VDS, where impact ionization is not of importance. The comparison between intrinsic MC simulation results for isolated-gate and Schottky-gate HEMTs reveals a strong influence of the native oxide on the dynamic behavior of the devices, mainly on C gs , g m and f c .
|
|
| 7. |
- Rodilla, H., et al.
(författare)
-
Monte Carlo study of the noise performance of isolated-gate InAs HEMTs
- 2011
-
Ingår i: 21st International Conference on Noise and Fluctuations, ICNF 2011; Toronto, ON; 12 June 2011 through 16 June 2011. - 9781457701924 ; , s. 184-187
-
Konferensbidrag (refereegranskat)abstract
- In this work, the noise performance of an InAs/AlSb 225-nm isolated-gate HEMT has been studied by means of Monte Carlo (MC) simulations. Firstly, the experimental DC behavior and the intrinsic small signal equivalent circuit parameters have been adequately reproduced in order to validate the model. Then, the extrinsic T and max have been obtained and compared with experimental data, getting a good agreement for T but some discrepancies for max . Finally, the intrinsic and extrinsic noise characteristics of the InAs based HEMT have been simulated, showing an excellent noise performance (F min =0.3 dB@10 GHz), comparable to that obtained in InGaAs HEMTs with a much shorter gate length of 50 nm. © 2011 IEEE.
|
|
| 8. |
- Vasallo, Beatriz G., et al.
(författare)
-
Monte carlo analysis of impact ionization in isolated-gate InAs/AlSb high electron mobility transistors
- 2011
-
Ingår i: Acta Physica Polonica A. - 0587-4246 .- 1898-794X. ; 119:2, s. 222-224
-
Konferensbidrag (refereegranskat)abstract
- We perform a physical analysis of the kink effect in InAs/AlSb high electron mobility transistors by means of a semiclassical 2D ensemble Monte Carlo simulator. Due to the small bandgap of InAs, InAs/AlSb high electron mobility transistors are very susceptible to suffer from impact ionization processes, with the subsequent hole transport through the structure, both implicated in the kink effect. When the drain-to-source voltage VDS is high enough for the onset of impact ionization, holes generated tend to pile up at the gate-drain side of the buffer. This occurs due to the valence-band energy barrier between the buffer and the channel. Because of this accumulation of positive charge, the channel is further opened and the drain current I D increases, leading to the kink effect in the I-V characteristics.
|
|
| 9. |
- Vasallo, Beatriz G., et al.
(författare)
-
Monte Carlo study of kink effect in isolated-gate InAs/AlSb high electron mobility transistors
- 2010
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 108:9
-
Tidskriftsartikel (refereegranskat)abstract
- A semiclassical two-dimensional ensemble Monte Carlo simulator is used to perform a physical analysis of the kink effect in InAs/AlSb high electron mobility transistors (HEMTs). Kink effect, this is, an anomalous increase in the drain current I-D when increasing the drain-to-source voltage V-DS, leads to a reduction in the gain and a rise in the level of noise, thus limiting the utility of these devices for microwave applications. Due to the small band gap of InAs, InAs/AlSb HEMTs are very susceptible to suffer from impact ionization processes, with the subsequent hole transport through the structure, both implicated in the kink effect. The results indicate that, when V-DS is high enough for the onset of impact ionization, holes thus generated tend to pile up in the buffer (at the gate-drain side) due to the valence-band energy barrier between the buffer and the channel. Due to this accumulation of positive charge the channel is further opened and I-D increases, leading to the kink effect in the I-V characteristics and eventually to the device electrical breakdown. The understanding of this phenomenon provides useful information for the development of kink-effect-free InAs/AlSb HEMTs.
|
|
