In situ transmission electron microscopy analysis of electron beam induced crystallization of amorphous marks in phase-change materials

\u3cp\u3eThe crystallization of melt-quenched amorphous data marks in a crystalline (Ga\u3csub\u3e15\u3c/sub\u3eSb\u3csub\u3e85\u3c/sub\u3e) phase-change layer from rewritable disks by transmission electron microscopy was discussed. Electron irradiation induced crystallization was obtained at room temperature by using a 120 kV. A comparison with laser-crystallized amorphous marks was made. An electron beam (e \u3csup\u3e-\u3c/sup\u3e beam) induced crystallization started from the amorphous crystalline interface. A dependence of growth velocity on e\u3csup\u3e-\u3c/sup\u3e beam intensity and growth direction was observed.\u3c/p\u3

In situ transmission electron microscopy observations of individually selected freestanding carbon nanotubes during field emission

\u3cp\u3eFor the successful application of carbon nanotubes (CNTs) as electron sources in various applications it is important to understand the relation between the morphology of the CNT and its emission properties. A method was developed to study individual, freestanding and pre-selected CNTs with high-resolution transmission electron microscopy (TEM). The technique provided important parameters of the CNT, such as the number of carbon walls and the nature of its apex. The resolution with which the freestanding apices were imaged depended linearly on the ratio of the length and the radius. CNTs were also imaged in situ in the TEM while emitting electrons. It was found that the structure of a CNT was highly stable below a certain threshold emission current of typically 2 μA, while various structural changes occurred above the threshold, leading to either damaging or repair of the structure at the apex of the CNT.\u3c/p\u3

Microscopic studies of polycrystalline nanoparticle growth in free space

We have extensively studied by multiple microscopic techniques the growth and crystallization of silicon nanoparticles in pulsed SiH4/Ar plasmas. We observe that the crystallinity of the particles can be tuned from amorphous to crystalline by altering the plasma ON time, tON. Three phases can be identified as a function of tON. Microscopic studies reveal that, in the initial gas phase (phase I) single particles of polycrystalline nature are formed which according to our hypothesis grow out of a single nucleus. The individual crystallites of the polycrystalline particles become bigger crystalline regions which marks the onset of cauliflower shaped particles (phase II). At longer tON (phase III) distinct cauliflower particles are formed by the growth of these crystalline regions by local epitaxy

Bidirectional modulation of reward-guided decision making by dopamine

Data and code of a project investigating dopaminergic effects on reward-guided decision makin

Microscopic studies of polycrystalline nanoparticle growth in free space

We have extensively studied by multiple microscopic techniques the growth and crystallization of silicon nanoparticles in pulsed SiH4/Ar plasmas. We observe that the crystallinity of the particles can be tuned from amorphous to crystalline by altering the plasma ON time, tON. Three phases can be identified as a function of tON. Microscopic studies reveal that, in the initial gas phase (phase I) single particles of polycrystalline nature are formed which according to our hypothesis grow out of a single nucleus. The individual crystallites of the polycrystalline particles become bigger crystalline regions which marks the onset of cauliflower shaped particles (phase II). At longer tON (phase III) distinct cauliflower particles are formed by the growth of these crystalline regions by local epitaxy

2D dopant profiling of advanced CMOS technologies by preferential etching, comparison with 2D process simulations

\u3cp\u3eIn this paper the possibilities for quantitative determination of 2D dope profiles in advanced CMOS technologies are investigated using selective etching in combination with TEM, SIMS and AFM. Promising results were obtained for As. For B an etch-rate dependence on the steepness of the B concentration gradient and influence of the background channel doping (As and P) seem to trouble quantification. A comparison between the measured and simulated (TSUPREM4) 2D profile of a 0.18ìm NMOST is presented.\u3c/p\u3

Gas phase grown silicon germanium nanocrystals

\u3cp\u3eWe report on the gas phase synthesis of highly crystalline and homogeneously alloyed Si\u3csub\u3e1−x\u3c/sub\u3eGe\u3csub\u3ex\u3c/sub\u3e nanocrystals in continuous and pulsed plasmas. Agglomerated nanocrystals have been produced with remarkable control over their composition by altering the precursor GeH\u3csub\u3e4\u3c/sub\u3e gas flow in a continuous plasma. We specially highlight that in the pulsed plasma mode, we obtain quantum-sized free standing alloy nanocrystals with a mean size of 7.3 nm. The presence of Si\u3csub\u3e1−x\u3c/sub\u3eGe\u3csub\u3ex\u3c/sub\u3e alloy particles is confirmed with multiple techniques, i.e. Raman spectroscopy, XRD (Xray diffraction) and HRTEM (high resolution transmission electron microscopy) studies, with each of these methods consistently yielding the same composition. The nanocrystals synthesized here have potential applications in band-gap engineering for multijunction solar cells.\u3c/p\u3

A manufacturable sub-50nm PMOSFET technology

\u3cp\u3eOne of the major problems during the processing of PMOS devices is the excessive diffusion of boron source and drain regions. Plasma enhanced CVD can be used to reduce the thermal budget associated with layer depositions between source/drain implants and back end. It also gives a possibility to selectively etch deposited layers to allow novel processing sequences. Here we study these possibilities and show that by using highquality PECVD depositions, we can engineer the appropriate for sub-50nm generation PMOS device architectures.\u3c/p\u3