| 1. |
- Desplanque, L., et al.
(författare)
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AlSb nucleation induced anisotropic electron mobility in AlSb/InAs heterostructures on GaAs
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 100:26
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the growth conditions at the AlSb/GaAs interface on the electron mobility in AlSb/InAs heterostructures is investigated. We show that an excessive antimony flux during the initial stage of the AlSb buffer growth leads to a strong anisotropy of electron mobility in InAs between [110] and [1-10] crystallographic orientations. This anisotropy is attributed to the formation of trenches oriented along the [1-10] direction in the InAs channel. Transmission electron microscopy reveals that these trenches are directly related to twinning defects originating from the AlSb/GaAs interface.
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| 2. |
- Ducournau, G., et al.
(författare)
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200 GHz communication system using unipolar InAs THz rectifiers
- 2013
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Ingår i: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. - 9781467347174
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Konferensbidrag (refereegranskat)abstract
- We report on the first use of a THz detector based on InAs rectifying nanochannels in a communication system. The transmitter is composed of an electronic multiplication chain, externally amplitude modulated at the input signal. The system has been driven at 200 GHz and up to 500 Mbps data signals have been transmitted in an indoor configuration. In contrast to most nanodevices, the InAs detector has a low impedance (580 ω) and is therefore easily loaded by 50 ω electronics. The data rate limitation is mainly coming from parasitics coupled in the board. © 2013 IEEE.
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| 3. |
- Lefebvre, Eric, 1975, et al.
(författare)
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Comparison of shallow-mesa InAs/AlSb HEMTs with and without early-protection for long-term stability against Al(Ga)Sb oxidation
- 2014
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Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 1361-6641 .- 0268-1242. ; 29:3
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Tidskriftsartikel (refereegranskat)abstract
- The fabrication process of InAs/AlSb high electron mobility transistors (HEMTs) has been improved by depositing, after the shallow-mesa isolation of the active area, a thin SiNx-film on the exposed AlGaSb mesa floor. Devices with and without this early-protection against Al(Ga)Sb oxidation have been fabricated simultaneously on the same chip for fair comparison. Optical observations and electrical measurements over four and half years demonstrated the physical stability provided by this extra-coverage. The electrical measurements also revealed that the induced deposition of the probing pads and of the extrinsic part of the gates on SiNx slightly reduced the maximum drain current I-D (-9%) and the transconductance g(m) (-12%) to, respectively, 700 mA mm (1) and 1220 mS mm (1) for 2 x 20 mu m(2) InAs/AlSb HEMTs with a 140 nm recessed gate. On the other hand, the gate-leakage current I-G was lowered by more than one order of magnitude, leading to a better pinch-off behavior and increased values of cut-off frequency f(T) (+4%) and maximum frequency of oscillation f(max) (+36%) to, respectively, 230 GHz and 190 GHz at a drain voltage V-DS of 0.5 V.
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| 4. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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Anisotropic transport properties in InAs/AlSb heterostructures
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 97:24, s. 3-
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the anisotropic transport behavior of InAs/AlSb heterostructures grown on a(001) InP substrate. An electrical analysis showed anisotropic sheet resistance Rsh and electronmobility μn in the two dimensional electron gas (2DEG). Hall measurements demonstrated anenhanced anisotropy in μn when cooled from room temperature to 2 K. High electron mobilitytransistors exhibited 27% higher maximum drain current IDS and 23% higher peak transconductancegm when oriented along the [1-10] direction. The anisotropic transport behavior in the 2DEG wascorrelated with an asymmetric dislocation pattern observed in the surface morphology and bycross-sectional microscopy analysis of the InAs/AlSb heterostructure.
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| 5. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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Cryogenic InAs/AlSb HEMT Wideband Low-Noise IF Amplifier for Ultra-Low-Power Applications
- 2012
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 22:3, s. 144-146
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Tidskriftsartikel (refereegranskat)abstract
- A cryogenic wideband 4-8 GHz hybrid low-noise amplifier, based on a 110 nm gate length InAs/AlSb HEMT process is presented. At room temperature the three-stage amplifier exhibited a transducer gain of 29 dB and a noise temperature of 150 K with 17.6 mW power consumption. When cooled to 13 K, the amplifier showed a minimum noise temperature of 19 K at a power consumption of 6 mW (66% reduction compared to room temperature). At cryogenic temperature, the optimum drain voltage for best noise performance was reduced from 0.55 V down to 0.3 V, demonstrating the very low-power and low-voltage capabilities of InAs/AlSb HEMT based low-noise amplifiers at cryogenic temperature.
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| 6. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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Cryogenic Operation of InAs/AlSb HEMT Hybrid LNAs
- 2012
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Ingår i: 15th European Microwave Week - Space for Microwaves Conference Proceedings. Amsterdam, NETHERLANDS. OCT 28-NOV 02, 2012. - 9782874870286 ; , s. 373-376
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Konferensbidrag (refereegranskat)abstract
- The suitability of InAs/AlSb HEMTs for cryogenic ultra low-power applications is investigated. Compared to room temperature, the device exhibited significantly improved drain current saturation, higher peak transconductance and lower gate current leakage at around 10 K. When tested in a three-stage hybrid 4-8 GHz LNA under cryogenic conditions, the LNA noise figure was 0.27 dB at an extremely low power consumption of 0.6 mW per stage.
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| 7. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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DC, RF and noise performance of InAs/AlSb HEMTs with in situ CVD SiNx-film for early-protection against oxidation
- 2013
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101. ; 87, s. 85-89
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Tidskriftsartikel (refereegranskat)abstract
- A new method for avoiding air exposure of the mesa-floor during processing of shallow-mesa InAs/AlSb HEMTs is reported. The method is based on the in situ chemical vapor deposition (CVD) of a SiNx-film, right after the shallow-mesa dry-etch process. The in situ CVD method allows also growing a dielectric film up to five times thicker than in previous reports of similar early-protection approach. Devices featuring a 25 nm SiNx-film enabled by the in situ CVD method are compared to devices based on a previously developed process, where the mesa floor is protected by a 2 nm SiNx-film deposited by ex situ reactive sputtering (RS). Microscopy observations revealed that the new process is more robust, ensuring a long-term stability against oxidation. DC, RF and noise performance were measured for 110 nm gate-length HEMTs. Devices based on the CVD process demonstrated higher peak transconductance (+13%), elevated I-on/I-off ratio (factor 4.7) and one order of magnitude lower gate current leakage. The cut-off frequency f(T) and the maximum oscillation frequency f(max) at a drain-source voltage of 0.3 V increased up to 175 GHz (+20%) and 130 GHz (+18%), respectively. Moreover, the extracted minimum noise figure for the InAs/AlSb HEMT using the in situ CVD early-protection was 1.4 dB at 6 GHz, instead of 2.3 dB for the RS based devices.
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| 8. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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InAs/AlSb HEMTs for cryogenic LNAs at ultra-low power dissipation
- 2011
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101. ; 64:1, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- Properties of the InAs/AlSb high electron mobility transistor, essential for the design of a cryogenic low-noise amplifier (LNA) operating at low power dissipation, have been studied. Upon cooling from 300 K to 77 K. the dc transconductance g(m) was enhanced by 30% at a drain-source voltage V(DS) of 0.1 V. The gate current leakage showed a strong reduction of the Schottky current component at 77 K. Compared to 300 K, the cut-off frequency f(T) and maximum oscillation frequency f(max) showed a significant improvement at 77 K with a peak f(T) (f(max)) of 167 (142) GHz at V(DS) = 0.2 V. The suitability of the Sb HEMT for a cryogenic LNA design up to 50 GHz, operating at low dc power dissipation, was investigated through the extraction of the NF(tot,min) figure of merit. It was found that the best device performance in terms of noise and gain is achieved at a low V(DS) of 0.16 v resulting in a minimum NF(tot,min) of 0.6 dB for a frequency of 10 GHz when operating at 77 K. A benchmarking between the Sb HEMT and an InP HEMT has been conducted highlighting the device improvement in noise and gain required to reach today's state-of-the-art cryogenic LNAs.
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| 9. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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Planar InAs/AlSb HEMTs With Ion-Implanted Isolation
- 2012
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Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 33:4, s. 510-512
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Tidskriftsartikel (refereegranskat)abstract
- The fabrication and performance of planar InAs/AlSb high-electron-mobility transistors (HEMTs) based on ion-implantation isolation technology are reported. Ar atoms have been implanted at an energy of 100 keV and with a dose of 2 x 10(15) cm(-2) in order to induce device isolation. The InAs/AlSb HEMT exhibited a maximum drain current of 900 mA/mm, a peak transconductance of 1180 mS/mm, and an f(T)/f(max) ratio of 210 GHz/180 GHz at a low drain bias of 0.3 V. The combination of excellent stability against oxidation with the high device isolation demonstrated by the implantation technique can dramatically improve the suitability of InAs/AlSb HEMTs for high-frequency and ultralow-power MMIC applications.
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| 10. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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Source-drain scaling of ion-implanted InAs/AlSb HEMTs
- 2012
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Ingår i: Indium Phosphide and Related Materials (IPRM), 2012 International Conference on. - : IEEE. - 1092-8669. - 9781467317252 ; , s. 57-60
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Konferensbidrag (refereegranskat)abstract
- We report on the lateral scaling of true planar InAs/AlSb high electron mobility transistors (HEMTs) based on ion implantation for device isolation. When reducing the source drain distance, dsd, from 2.5 μm to 1 μm, the HEMTs showed up to 56% higher maximum drain current, 23% higher peak transconductance and T of 185 GHz (+32%). A trade-off in the lateral scaling is needed due to increased gate leakage current and pinch-off degradation for dsd below 1.5 μm. The ability to withstand oxidation of the InAs/AlSb heterostructure makes the planar technology based on ion implantation extremely promising for MMIC integration of InAs/AlSb HEMTs.
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| 11. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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True planar InAs/AlSb HEMTs with ion-implantation technique for low-power cryogenic applications
- 2013
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101 .- 1879-2405. ; 79, s. 268-273
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we report the room-temperature and cryogenic properties of true planar 110 nm InAs/AlSb HEMTs fabricated with Ar-ion isolation technology. Device isolation is generally improved and is in particular increased by four orders of magnitude at 6 K compared to 300 K. This results in improved drain current saturation, lower gate leakage current and 23% higher peak transconductance. The RF performance is significantly improved as well, with 47% higher f(T) (162 GHz) and 72% higher f(max) (155 GHz) at the low drain voltage of 0.1 V, compared to room temperature. The overall performance of the fabricated devices shows the suitability of ion implantation for the device isolation at cryogenic temperature. Furthermore, the excellent stability against oxidation and truly planar structure of these devices demonstrate great potential for highly integrated cryogenic millimeter-wave circuits in InAs/AlSb technology with ultra-low power consumption.
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| 12. |
- Noudeviwa, A., et al.
(författare)
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Sb-HEMT: Toward 100-mV Cryogenic Electronics
- 2010
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 57:8, s. 1903-1909
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a first full set of characteristics (dc, f(T), f(max), and noise) of InAs/AlSb high-electron mobility transistors (HEMTs) operating under cryogenic temperature and low-power conditions. Those results are systematically compared and deeply analyzed at room temperature and 77 K. The characteristics improvement achieved at 77 K open up the possibility to develop ultralow-power cryogenic electronics (low-noise amplifier), featuring excellent high-frequency/noise performances below 100-mV dc biasing.
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| 13. |
- Westlund, Andreas, 1985, et al.
(författare)
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Cryogenic DC Characterization of InAs/Al80Ga20Sb Self-Switching Diodes
- 2013
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Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - 1092-8669. - 9781467361316
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Konferensbidrag (refereegranskat)abstract
- DC characterization of an InAs/Al80Ga20Sb self-switching diode for THz detection is presented at 300 K and 6 K. Compared to 300 K, an enhancement of the diode I-V nonlinearity and associated responsivity was observed under zero-bias conditions at 6 K. The intrinsic responsivity was estimated to 490 V/W at 300 K and 4400 V/W at 6 K.
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| 14. |
- Westlund, Andreas, 1985, et al.
(författare)
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Nanochannel diodes based on InAs/Al80Ga20Sb heterostructures: Fabrication and zero-bias detector properties
- 2015
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Ingår i: Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics. - : American Vacuum Society. - 2166-2746 .- 2166-2754. ; 33:2, s. 021207-
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Tidskriftsartikel (refereegranskat)abstract
- The authors present a novel process for fabrication of deep submicron isolation patterns in InAs/Al80Ga20Sb heterostructures. The process is demonstrated by processing InAs/Al80Ga20Sb self-switching diodes (SSDs). SSDs require high-resolution isolation patterns, which presents a major fabrication challenge because of the oxidation sensitivity of Al(Ga)Sb alloys. The presented fabrication process completely avoided exposure of Al(Ga)Sb to air and resulted in an isolation pattern with a feature size down to 35 nm. The process was based on a dry etch of isolating trenches, in situ removal of the resist etch mask followed by in situ encapsulation of etched surfaces by silicon nitride. The applicability of the InAs/Al80Ga20Sb SSD process was demonstrated with on-wafer RF measurements of zero-bias detection up to 315 GHz. Below 50 GHz, the detector's noise equivalent power was estimated to less than 100 pW/Hz½ .
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| 15. |
- Westlund, Andreas, 1985, et al.
(författare)
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On the effect of delta-doping in self-switching diodes
- 2014
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 105:9, s. Article Number: 093505 -
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Tidskriftsartikel (refereegranskat)abstract
- Lowering the carrier concentration is presented as a way to considerably improve the performance of self-switching diode (SSD) detectors. A physics-based theoretical model was used to derive an expression for the responsivity of SSDs as a function of carrier concentration, mobility, and design parameters. Monte Carlo simulations confirmed the modeled effect of varying carrier concentration and channel width. SSDs were fabricated in InAs heterostructures with different delta-doping levels. Radio frequency (RF) characterization at 50 GHz reproduced the modeled trends. By reducing the carrier concentration in InAs SSDs with 40 nm wide channels from 2.7 x 10(12) cm(-2) to 1.5 x 10(12) cm(-2) (-44%), the noise equivalent power (NEP) improved from 130 pW/Hz(1/2) to 87 pW/Hz(1/2) (-33%).
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| 16. |
- Westlund, Andreas, 1985, et al.
(författare)
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Optimization and small-signal modeling of zero-bias InAs self-switching diode detectors
- 2015
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101. ; 104:Feb, s. 79-85
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Tidskriftsartikel (refereegranskat)abstract
- Design optimization of the InAs self-switching diode (SSD) intended for direct zero-bias THz detection is presented. The SSD, which consists of nanometer-sized channels in parallel, was described using an equivalent small-signal circuit. Expressions for voltage responsivity and noise equivalent power (NEP) were derived in terms of geometrical design parameters of the SSD, i.e. the channel length and the number of channels. Modeled design dependencies were confirmed by RF and DC measurements on InAs SSDs. In terms of NEP, an optimum number of channels were found with the detector driven by a 50 Omega source. With a matched source, the model predicted a responsivity of 1900 V/W and NEP of 7.7 pW/Hz(1/2) for a single-channel InAs SSD with 35 nm channel width. Monte Carlo device simulations supported observed design dependencies. The proposed small-signal model can be used to optimize SSDs of any material system for low-noise and high-frequency operation as zero-bias detectors. In large signal measurements, the responsivity of the InAs SSDs exhibited a 1 dB deviation from linear responsivity at an input power of -3 dBm from a 50 Omega source.
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| 17. |
- Westlund, Andreas, 1985, et al.
(författare)
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Terahertz detection in zero-bias InAs self-switching diodes at room temperature
- 2013
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 103:13
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Tidskriftsartikel (refereegranskat)abstract
- RF characterization of InAs self-switching diodes (SSDs) is reported. On-wafer measurements revealed no roll-off in responsivity in the range of 2-315 GHz. At 50 GHz, a responsivity of 17 V/W and a noise-equivalent power (NEP) of 150 pW/Hz(1/2) was observed for the SSD when driven by a 50 Omega source. With a conjugately matched source, a responsivity of 34 V/W and an NEP of 65 pW/Hz(1/2) were estimated. An antenna-coupled SSD demonstrated a responsivity of 0.7 V/W at 600 GHz. The results demonstrate the feasibility of zero-bias terahertz detection with high-electron mobility InAs SSDs up to and beyond 100 GHz.
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