Structural transformation in C/Si multilayer after annealing

Amorphous C/Si multilayers were prepared by DC magnetron sputtering technique and investigated by transmission electron microscopy and low-angle x-ray diffraction methods after annealing at 650 and 950 °C. The amorphous interlayers of 0.5 − 0.6 nm thick were found at C/Si and Si/C interfaces being of different density and composition. Amorphous structure of the multilayer is stable up to 950 °C when crystallization of α-SiC occurs and voids form in α-Si layer.Изготовленные методом прямоточного магнетронного распыления аморфные многослойные композиции C/Si были исследованы методами просвечивающей электронной микроскопии и малоугловой рентгеновской дифракции после отжигов при температуре 650 и 950 °C. На границах раздела C/Si и Si/C обнаружены аморфные перемешанные зоны толщиной 0.5 – 0.6 нм c различными плотностью и составом. Аморфная структура многослойной композиции стабильна вплоть до 950 °C, когда наблюдается формирование пор в слоях α-Si и кристаллизация α-SiC.Виготовлені методом прямоточногомагнетронного розпилення аморфні багатошарові композиції C/Si було досліджено методами просвічувальної електронної мікроскопії та малокутової рентгенівської дифракції після відпалу при температурі 650 і 950 °C. На межах поділу C/Si та Si/C виявлені аморфні перемішані зони різної густини та складу завтовшки 0.5 – 0.6 нм. Аморфна структура багатошарової композиції є стабільною до 950 °C, коли спостерігається формування пор у шарах α-Si у та кристалізація α-SiC

Nanoscale Co/C multilayers for "carbon window" Schwarzchild objective

The formation features of the Co/C multilayer with ≈2.3 nm period have been studied with aim to form a Schwarzschild objective on a "carbon window" for medical and biological investigations. A sequence of multilayer deposition on curved substrates has been proposed that provides the matched functioning of both objective mirrors. The interaction features of the Co and C layers during deposition, period and reflectivity changes under heating have been considered

Initial stages of diffusion and phase formation in Sc/Si layered systems

Kinetics of phase formation Sc/Si multilayers and Si/Sc/Si three-layers within the temperature range of 130-400°C has been studied by cross-sectional transmission electron microscopy and small-angle X-ray reflectometry. Growth of ScSi silicide governed by diffusion kinetics was observed at all temperatures. Two growth stages of nonparabolic and parabolic behavior were revealed. Initial nonparabolic stage is characterized by higher diffusion coefficient, which decreases during annealing in 20 times due to silicide structural relaxation. After annihilation of excess free volume a transition to parabolic growth takes place. Parameters of interdiffusion (activation energy E ≈1 eV and pre-exponential factor D₀ = 4.10⁻¹² m²s⁻¹) were determined for parabolic growth stage

Formation and evolution of intermixing zones in C/Si multilayer under heating

Formation of intermixing zones, their structure and phase composition in C/Si multilayers in as-deposited state and after annealing are studied. During deposition intermixing zones of ∼ 0.6 m thick are formed at both silicon/carbon and carbon/silicon interfaces. The zone formed at C-on-Si interlayer is denser than adjacent zone due to amorphous SiC nucleation. Both the thickness and the densities of intermixing zones increase with annealing temperature up to 800°C. Silicon carbide is revealed in Si-on-C zone at 700°C. Structure of the zones is still amorphous at 950°C