Stress and magnetoelastic properties control of amorphous Fe80B20 thin films during sputtering deposition

Abstract

In situ stress measurements during sputtering deposition of amorphous Fe 80 B 20 films are used to control their stress and magnetoelastic properties. The substrate curvature induced by the deposited film is measured optically during growth and quantitatively related to the deposition induced accumulated stress. The resulting magnetic properties are later correlated with the measured stress for a wide range of sputtering pressures ͓͑2−25͒ ϫ 10 −3 mbar͔. A significant tensile stress develops at the film-substrate interface during the early growth stages ͑initial 2-3 nm͒. At a critical thickness, a transition is observed from tensile to compressive stress, which is associated with amorphous island coalescence. By further increasing the thickness, a compressive stress follows, which is related to the local distortion induced by the ion peening effect. The Monte Carlo simulations of the sputtering process describe quantitatively the experimental results as a function of the Ar pressure and target bias voltage.

Structural and optical changes induced by incorporation of antimony into InAs/GaAs(001) quantum dots

“…Highly sensitive in situ optical measurements of the substrate curvature were used to measure the accumulated stress ͑⌺͒ evolution during heteroepitaxial growth. 21,22 The samples are cantilever shaped ͑typically 5 ϫ 20 mm 2 ͒ GaAs substrates with a thickness of 100 m, mechanically clamped on one end, while the other end is free to move. The angle of reflection of a laser beam was compared at the clamped end and the free end of the substrate.…”

Saturation magnetostriction of α″-Fe16N2 phase

“…The value || /2 / = 1 indicates the existence of anisotropy of the demagnetized state. The quantity s = (2/3) || − ⊥ remains independent of the demagnetized state [15,16]. A special device for direct measurement of magnetostrictions || and ⊥ has been constructed [14].…”

“…In this paper, the saturation magnetostriction of ␣ -Fe 16 ribbon with ␣ -Fe 16 N 2 crystallites embedded in an amorphous matrix.…”

Magnetic properties of current-annealed amorphous thin films

“…[11][12][13][14] The ability to control their microstructure through conventional thermal treatments is sometimes limited by the choice of the substrate, as glass cannot be heated at very high temperatures, and silicon may be affected by diffusion of some metals through its interface with the film. On the contrary, Joule heating, provided that an electrically insulating substrate is chosen, could be a viable technique for annealing the metallic film (and consequently tailoring its microstructure and its physical properties) without significantly affecting the substrate and its interface with the deposited metallic layer.…”