Sergey Grachev
Saint-Gobain
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Publication
Featured researches published by Sergey Grachev.
Journal of Applied Physics | 2014
Ronny Knut; Rebecka Lindblad; Sergey Grachev; Jean-Yvon Faou; Mihaela Gorgoi; Håkan Rensmo; Elin Sondergard; Olof Karis
The chemistry and intermixing at buried interfaces in sputter deposited ZnO/Ti/ZnO thin layers were studied by hard x-ray photoelectron spectroscopy. The long mean free path of the photoelectrons a ...
Applied Physics Letters | 2013
Jesse R. Williams; Hirokazu Furukawa; Yutaka Adachi; Sergey Grachev; Elin Sondergard; Naoki Ohashi
The structures and properties of zinc oxide thin films deposited by radio-frequency magnetron sputtering were investigated for different substrate biases applied during deposition. The electrical bias determined the crystalline polarity of a nominally undoped film on an amorphous substrate: films with a (0001) surface and a (0001¯) surface were produced under positive and negative biases, respectively. Moreover, the polarity of the films was determined at an early stage of the deposition and could not be reversed by switching the substrate bias.
MRS Proceedings | 2009
Arif Sinan Alagoz; Jan-Dirk Kamminga; Sergey Grachev; Toh-Ming Lu; Tansel Karabacak
Control of residual stress in thin films is critical in obtaining high mechanical quality coatings without cracking, buckling, or delamination. In this work, we present a simple and effective method of residual stress reduction in sputter deposited thin films by stacking low and high material density layers of the same material. This multilayer density modulated film is formed by successively changing working gas pressure between high and low values, which results in columnar nanostructured and dense continuous layers, respectively. In order to investigate the evolution of residual stress in density modulated thin films, we deposited ruthenium (Ru) films using a DC magnetron sputtering system at alternating argon (Ar) pressures of 20 and 2 mTorr. Wafer’s radius of curvature was measured to calculate the intrinsic thin film stress of multilayer Ru coatings as a function of total film thickness by changing the number of high density and low density layers. By engineering the film density, we were able to reduce film stress more than one order of magnitude compared to the conventional dense films produced at low working gas pressures. Due to their low stress and enhanced mechanical stability, we were able to grow these density modulated films to much higher thicknesses without suffering from buckling. Morphology and crystal structure of the thin films were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). A previously proposed model for stress reduction by means of relatively rough and compliant sublayers was used to explain the unusually low stress in the specimens investigated.
Materials Science Forum | 2011
Christopher Krauss; G. Geandier; Florine Conchon; Pierre Olivier Renault; Eric Le Bourhis; Alessandro Benedetto; Sergey Grachev; P. Goudeau; Etienne Barthel
Residual stress relaxation in sputtered ZnO films has been studied in-situ by synchrotron x-ray diffraction. The films deposited on (001) Si substrates were thermally treated from 25°C to 700°C. X-ray diffraction 2D patterns were captured continuously during the heating, plateau and cooling ramps. The corrections carried out for compensating the furnace drift are discussed. We first observe an increase of the intrinsic compressive stresses before stress relaxation starts to operate around 370°C. Then, thermal contraction upon cooling dominates so that overall, the large initial compressive film stresses turn to tensile after thermal treatment. The overall behaviour is discussed in terms of structural changes induced by the heat treatment.
MRS Proceedings | 2009
Florine Conchon; Pierre-Olivier Renault; P. Goudeau; Eric Le Bourhis; Elin Sondergard; Etienne Barthel; Sergey Grachev; Eric Gouardes; Veronique Rondeau; Rene Gy; Rémi Lazzari; Jacques Jupille; Nathalie Brun
Residual stresses in sputtered ZnO films on Si are investigated and discussed. By means of X-ray diffraction, we show that as-deposited ZnO films encapsulated or not by Si 3N4 protective coatings are highly compressively stressed. Moreover, a transition of stress is observed as a function of the post-deposition annealing temperature. After a heat treatment at 800°C, ZnO films are tensily stressed while ZnO films encapsulated by Si 3N4 are stress-free. With the aid of in-situ X-ray diffraction, we argue that this thermally-activated stress relaxation can be attributed to a variation of the chemical composition of the ZnO films.
MRS Proceedings | 2009
Sergey Grachev; Coraly Cuminatto; Elin Sondergard; Etienne Barthel
Another important film property is the residual stress. Using the wide range of buckle sizes generated by the thickness and adhesion gradients, we investigate the buckle morphology in details. The results indicate that the ratio between the height and an in-plane width of a telephone-cord like blister can be used to assess the value of the biaxial stress in the compressed layer. Finally we suggest that further understanding of the relation between buckle morphology and interfacial toughness is highly desirable.
Physical Review Letters | 2012
Jean-Yvon Faou; Guillaume Parry; Sergey Grachev; Etienne Barthel
Journal of Physics D | 2013
Sergey Grachev; Marco de Grazia; Etienne Barthel; Elin Sondergard; Rémi Lazzari
Journal of Luminescence | 2011
Alban Letailleur; Sergey Grachev; Etienne Barthel; Elin Sondergard; Komla Nomenyo; Christophe Couteau; Stefan Mc Murtry; Gilles Lerondel; Emilie Charlet; Emmanuelle Peter
Journal of The Mechanics and Physics of Solids | 2015
Jean-Yvon Faou; Guillaume Parry; Sergey Grachev; Etienne Barthel