ALD

In this work, we demonstrate various ohmic contact formation processes using an AlN/GaN (MOS)HEMT structure with an aluminum oxide gate dielectric formed by ALD. The MO-SHEMT structure is advantageous because the thin oxide layer protects the ultra-thin (~3 nm) AlN barrier against exposure to the processing chemicals. Contact resistance values as low as 0.457 Ω•mm are reported on TLM structures. The corresponding devices exhibited excellent electronic transport properties with room temperature mobility µ > 1000 cm 2 /V•s and sheet carrier concentration n S > 3.25 x 10 13 cm-2. These are the lowest contact resistance values obtained for AlN/GaN HEMTs in the high mobility range (> 1000 cm 2 /V•s).

ABSTRACT
Adrenoleukodystrophy (X-ALD) is a rare disease, its origin is genetic, and it affects the nervous system and the adrenal glands. People with this disease often have a progressive loss of the fatty covering (myelin) that surrounds the nerves in the brain and spinal cord.
It is caused by a mutation in the ABCD1 gene; it is inherited in an X link. There is still no cure for X-ALD but there are promising treatments and promising lines of research, which we will discuss. As it is a rare disease, it suffers from a "deficit" of medical, scientific and, above all, social and political knowledge. In fact, there was no specific research policy, at least in Argentina, until recently, which is why it must be intensify the research and social dissemination of these diseases, since this way we are also cooperating to get them out of that unknown threshold as is usually seen.

We report for the first time the preparation of highly stable graphene (GE)-based nanofluids with ionic liquid as base fluids (ionic liquid-based nanofluids (Ionanofluids)) without any surfactant and the subsequent investigations on their thermal conductivity, specific heat, and viscosity. The microstructure of the GE and MWCNTs are observed by transmission electron microscope. Thermal conductivity (TC), specific heat, and viscosity of these Ionanofluids were measured for different weight fractions and at varying temperatures, demonstrating that the Ionanofluids exhibit considerably higher TC and lower viscosity than that of their base fluids without significant specific heat decrease. An enhancement in TC by about 15.5% and 18.6% has been achieved at 25°C and 65°C respectively for the GE-based nanofluid at mass fraction of as low as 0.06%, which is larger than that of the MWCNT-dispersed nanofluid at the same loading. When the temperature rises, the TC and specific heat of the Ionanofluid increase clearly, while the viscosity decreases sharply. Moreover, the viscosity of the prepared Ionanofluids is lower than that of the base fluid. All these advantages of this new kind of Ionanofluid make it an ideal fluid for heat transfer and thermal storage.

Electrical and physical properties of a metal-oxide-semiconductor [MOS] structure using atomic layer-deposited high-k dielectrics (TiO 2 /Al 2 O 3 ) and epitaxial GaAs [epi-GaAs] grown on Ge(100) substrates have been investigated. The epi-GaAs, either undoped or Zn-doped, was grown using metal-organic chemical vapor deposition method at 620°C to 650°C. The diffusion of Ge atoms into epi-GaAs resulted in auto-doping, and therefore, an n-MOS behavior was observed for undoped and Zn-doped epi-GaAs with the doping concentration up to approximately 10 17 cm -3 . This is attributed to the diffusion of a significant amount of Ge atoms from the Ge substrate as confirmed by the simulation using SILVACO software and also from the secondary ion mass spectrometry analyses. The Zn-doped epi-GaAs with a doping concentration of approximately 10 18 cm -3 converts the epi-GaAs layer into p-type since the Zn doping is relatively higher than the out-diffused Ge concentration. The capacitance-voltage characteristics show similar frequency dispersion and leakage current for n-type and p-type epi-GaAs layers with very low hysteresis voltage (approximately 10 mV). PACS: 81.15.Gh.

In this work, we demonstrate various ohmic contact formation processes using an AlN/GaN (MOS)HEMT structure with an aluminum oxide gate dielectric formed by ALD. The MO-SHEMT structure is advantageous because the thin oxide layer protects the ultra-thin (~3 nm) AlN barrier against exposure to the processing chemicals. Contact resistance values as low as 0.457 Ω•mm are reported on TLM structures. The corresponding devices exhibited excellent electronic transport properties with room temperature mobility µ > 1000 cm 2 /V•s and sheet carrier concentration n S > 3.25 x 10 13 cm-2. These are the lowest contact resistance values obtained for AlN/GaN HEMTs in the high mobility range (> 1000 cm 2 /V•s).

Atomic-layer-deposited (ALD) aluminum oxide (Al2O3) has recently demonstrated an excellent surface passivation for both n- and p-type c-Si solar cells thanks to the presence of high negative fixed charges (Qf ∼ 1012−1013 cm−2) in combination with a low density of interface states (Dit). This paper in- vestigates the passivation quality of thin (15 nm) Al2O3 films deposited by two different techniques: plasma- enhanced atomic layer deposition (PE-ALD) and Thermal atomic layer deposition (T -ALD). Other dielec- tric materials taken into account for comparison include: thermally-grown silicon dioxide (SiO2) (20 nm), SiO2 (20 nm) deposited by plasma-enhanced chemical vapour deposition (PECVD) and hydrogenated amorphous silicon nitride (a-SiNx:H) (20 nm) also deposited by PECVD. With the above-mentioned di- electric layers, Metal Insulator Semiconductor (MIS) capacitors were fabricated for Qf and Dit extraction through Capacitance-Voltage-Conductance (C-V-G) measurements. In addition, lifetime measurements were carried out to evaluate the effective surface recombination velocity (SRV). The influence of extracted C-V-G parameters (Qf,Dit) on the injection dependent lifetime measurements τ(Δn), and the dominant passivation mechanism involved have been discussed. Furthermore we have also studied the influence of the SiO2 interfacial layer thickness between the Al2O3 and silicon surface on the field-effect passivation mechanism. It is shown that the field effect passivation in accumulation mode is more predominant when compared to surface defect passivation.