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Maximum post-process annealing temperature for standard 0.35 mu m CMOS wafers having aluminium based interconnections and tungsten plugs, is studied.

In this report we present the fabrication of superlattices consisting of heterogeneous magnetic GaAs:MnAs layers and InGaAs spacers with equal thickness. The magnetic and structural properties of such a superlattice are described, showing that under the appropriate annealing conditions the low-temperature grown superlattice structure is preserved and that the MnAs magnetic clusters can be formed in 2D sheets separated by thin (5-20 nm) semiconductor layers of good crystalline quality. CPP magnetotransport studies only show measurable MR at low temperatures, dominated by the dilute magnetic semiconductor Ga(Mn)As host lattice of the MnAs clusters. Index Terms - magnetic nano-particles, magnetic semiconductor hybrids, CPP magnetotransport

The structure, crystallinity and properties of as-deposited two-dimensional (2D) transition metal dichalcogenides are determined by nucleation mechanisms in the deposition process. 2D materials grown by atomic layer deposition (ALD) in the absence of a template are polycrystalline or amorphous. Little is known about their nucleation mechanisms. Therefore, the nucleation behavior of WS2 during plasma enhanced ALD from WF6, H2 plasma and H2S at 300 °C is investigated on amorphous ALD Al2O3 starting surface and on monocrystalline, bulk sapphire. Preferential interaction of the precursors with the Al2O3 starting surface promotes fast closure of the WS2 layer. The WS2 layers are fully continuous at WS2 content corresponding to only 1.2 WS2 monolayers. On amorphous Al2O3, (0002) textured and polycrystalline WS2 layers form with grain size of 5 to 20 nm due to high nucleation density (∼1014 nuclei/cm2). The WS2 growth mode changes from 2D (layer-by-layer) growth on the initial Al2O3 surface to three-dimensional (Volmer-Weber) growth after WS2 layer closure. Further growth proceeds from both WS2 basal planes in register with the underlying WS2 grain and from or over grain boundaries of the underlying WS2 layer with different in-plane orientation. In contrast, on monocrystalline sapphire, WS2 crystal grains can locally align along a preferred in-plane orientation. Epitaxial seeding occurs locally albeit a large portion of crystals remain randomly oriented, presumably due to the low deposition temperature. The WS2 sheet resistance is 168 MΩμm, suggesting that charge transport in the WS2 layers is limited by grain boundaries. [ABSTRACT FROM AUTHOR]

In this work, we report on wet-chemical defect revealing in InP fin structures relevant for device manufacturing. Both HCl and HBr solutions were explored using bulk InP as a reference. A distinct difference in pit morphology was observed between the two acids, attributed to an anisotropy in step edge reactivity. The morphology of the etch pits in bulk InP suggests that the dislocations are oriented mainly perpendicular to the surface. By studying the influence of the acid concentration on the InP fin recess in nanoscale trenches, it was found that aqueous HCl solution was most suitable for revealing defects. Planar defects in InP fin structures grown by the aspect ratio trapping technique could be visualized as characteristic shallow grooves approximately one nanometer deep. It is challenging to reveal defects in wide-field InP fins. In these structures, dislocations also reach the surface next to stack faults or twinning planes. Due to the inclined nature, dislocation-related pits are only a few atomic layers deep. Extending the pits is limited by the high reactivity of the fin sides and the strong surface roughening during etching. The process window for revealing wet-chemical defects in InP fins is limited. [ABSTRACT FROM AUTHOR]

The three-dimensional (3D) distribution of carbon nanotubes (CNTs) grown inside semiconductor contact holes is studied by electron tomography. The use of a specialized tomography holder results in an angular tilt range of ±90°, which means that the so-called "missing wedge" is absent. The transmission electron microscopy (TEM) sample for this purpose consists of a micropillar that is prepared by a dedicated procedure using the focused ion beam (FIB) but keeping the CNTs intact. The 3D results are combined with energy dispersive X-ray spectroscopy (EDS) to study the relation between the CNTs and the catalyst particles used during their growth. The reconstruction, based on the full range of tilt angles, is compared with a reconstruction where a missing wedge is present. This clearly illustates that the missing wedge will lead to an unreliable interpretation and will limit quantitative studies. [ABSTRACT FROM AUTHOR]

Abstract: We report on the synthesis of Cu3Ge films by exposing Cu films to germane (GeH4). The process window was established by investigating the influence of the GeH4 partial pressure, the soak temperature, and the soak time on Cu films of different thickness. It is shown that short exposures of germane led to Cu-rich germanides, while an excessive GeH4 supply resulted in a Cu3Ge/Ge mixed phase. The germanidation reaction was found to be selective and required the prior removal of the native Cu oxide by in situ plasma cleaning. X-ray diffraction and transmission electron microscopy showed that the Cu3Ge films were crystalline as deposited in the orthorhombic phase and were textured. The films were homogenous in composition. Thin films consisted of Cu3Ge islands connected by a thin wetting layer. Fully continuous layers were however found for larger film thicknesses. The continuity of the Cu3Ge film was also found to be influenced by the pseudosubstrate: the films were more continuous on TaN/Ta than on SiO2. The electric properties of the Cu3Ge films on both TaN/Ta and SiO2 pseudosubstrates are presented and compared. [Copyright &y& Elsevier]