The possibility to suppress undesirable diffusion of the base dopant boron in siliconbased bipolar transistor structures by the incorporation of a high concentration of carbon has lead to renewed interest in the behavior of carbon in crystalline silicon. The present paper will review essential features of carbon in silicon including solubility, diffusion mechanisms and precipitation behavior. Based on this information the possibilities to use carbon to influence diffusion of dopants in silicon by the introduction of non-equilibrium concentrations of intrinsic point defects will be discussed as well as the reason for the relatively high resilience against carbon precipitation. Interactions between carbon and oxygen will be mentioned, especially in the context of an as yet unexplained fast out-diffusion of carbon close to the surface.

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DAST (4-N,N-dimethylamino-4'-N'-methyl stilbazolium tosylate) is an organic salt with one of the highest nonlinear optical susceptibilities and electro-optical coefficients. DAST crystals are therefore seen as good candidates for many photonic applications such as microring resonators or for THz-devices. The quality of such organic crystal is crucial for any application. We discuss here two different growth methods of single crystalline DAST from solution. Bulk crystals, 1 cm3 in size, and thin crystals, 1 mm2 for a thickness of about 100 ?m are obtained. The use of a DAST crystal for a microring resonator is also presented

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At high concentrations, carbon in silicon shows some properties of technological interests like gap engineering, lattice engineering or the reduction of the so-called 'Transient Enhanced Diffusion' of some dopants. The carbon incorporation in concentrations above 1% is nevertheless a difficult task due to the low carbon solubility in silicon. Here, we present a systematic approach of the Si 1 − x C x layer growth by Molecular Beam Epitaxy (MBE). To study the influence of the growth temperature on the carbon incorporation, we deposit 100 nm thick silicon layers with different carbon concentrations separated by a 100 nm silicon spacer for different temperatures, ranging from 370 up to 800°C. In-situ Reflection High Energy Diffraction (RHEED), Secondary Ion Mass Spectroscopy (SIMS) and cross-sectional Transmission Electron Microscopy (TEM) have been performed to characterize the as-grown structures. We show the presence of two distinct growth phenomena, a 'classical' one, around 450°C, where carbon is mainly substitutionally incorporated, defect free until 2%; and a second one, above 550°C, showing an agglomeration of carbon in thin layers with presumably a very high local concentration, without any planar defects. We propose in this work a diagram of Si:C growth by MBE.