Stereometric Analysis of Effects of Heat Stressing on Micromorphology of Si Single Crystals

Silicon - The purpose of this work is study of silicon single crystal wafer thermal stability in correlation with three-dimensional (3D) surface characterization using atomic force microscopy...     

Multiferroic behavior of the functionalized surface of a flexible substrate by deposition of Bi2O3 and Fe2O3

Thin films of bismuth and iron oxides were obtained by atomic layer deposition (ALD) on the surface of a flexible substrate poly(4,4′-oxydiphenylene-pyromellitimide) (Kapton) at a temperature of 250°C. The layer thickness was 50 nm. The samples were examined by secondary-ion mass spectrometry, and uniform distribution of elements in the film layer was observed. Surface morphology, electrical polarization, and mechanical properties were investigated by atomic force microscope, piezoelectric force microscopy, and force modulation microscopy. The values of current in the near-surface layer varied in the range of ±80 pA when a potential of 5 V was applied. Chemical analysis was performed by X-ray photoelectron spectroscopy, where the formation of Bi₂O₃ and Fe₂O₃ phases, as well as intermediate phases in the Bi–Fe–O system, was observed. Magnetic measurements were carried out by a vibrating sample magnetometer that showed a ferromagnetic response. The low-temperature method of functionalization of the Kapton surface with bismuth and iron oxides will make it possible to adapt the Bi–Fe–O system to flexible electronics.     

Evaluation of the Topographical Surface Changes of Silicon Wafers after Annealing and Plasma Cleaning

Silicon - The morphological stability of silicon single crystal wafers was investigated, after performing cleaning surface treatments based on moderate temperature annealing and plasma sputtering....     

Atomic Layer Deposition of Aluminum Nitride Using Tris(diethylamido)aluminum and Hydrazine or Ammonia

Aluminum nitride (AlN _x ) films were obtained by atomic layer deposition (ALD) using tris(diethylamido) aluminum(III) (TDEAA) and hydrazine (N₂H₄) or ammonia (NH₃). The quartz crystal microbalance (QCM) data showed that the surface reactions of TDEAA and N2H4 (or NH₃) at temperatures from 150 to 225°C were self-limiting. The rates of deposition of the nitride film at 200°C for systems with N₂H₄ and NH₃ coincided: ~1.1 Å/cycle. The ALD AlN films obtained at 200°C using hydrazine had higher density (2.36 g/cm³, 72.4% of bulk density) than those obtained with ammonia (2.22 g/cm³, 68%). The elemental analysis of the film deposited using TDEAA/N2H4 at 200°C showed the presence of carbon (~1.4 at %), oxygen (~3.2 at %), and hydrogen (22.6 at %) impurities. The N/Al atomic concentration ratio was ~1.3. The residual impurity content in the case of N₂H₄ was lower than for NH₃. In general, it was confirmed that hydrazine has a more preferable surface thermochemistry than ammonia.