Thermodynamics of Passive Film Formation from First Principles

Abstract Kinetics of passive film formation on the bare surface of scratched stainless steels SS in magnesium chloride (MgCl2) solutions were studied using the rapid scratching technique under potentiostatic conditions. An experimental device was designed to record data at the rate of 20,000 points/s, with the rotating rate of the specimen at 3,000 rpm and a scratch scar length of about 4.6 mm to 4.8 mm. A new phenomenon was observed in that two peaks were seen rather than a continuous decay in the curve of current decay on scratched SS in MgCl2 solutions. Current decayed steeply to approximately passive current within about 2.5 ms to 3 ms after the diamond knife was moved away from the specimen. Current rose again for about 2 ms to 3 ms. This phenomenon was considered to represent the processes of adsorbed layer formation on the bare surface and transformation of the adsorbed layer into a passive film. Results were affected by the recording rate of experimental data, the specimen rotating rate, and the scratch scar length. The kinetics of passive film growth were shown empirically by i(t) = I0exp(−βt) with I0 and β being constants. Passive film growth was controlled by ion conduction in a strong electric field, as defined by i = A exp(BV/x).

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Optical and electrochemical studies of passive film formation in amorphous Ni‐Cr‐P‐C alloys

Journal of Applied Physics ◽

10.1063/1.344024 ◽

1989 ◽

Vol 66 (8) ◽

pp. 3942-3945

Author(s):

D. B. Hagan ◽

B. W. Sloope ◽

V. A. Niculescu

Keyword(s):

Passive Film ◽

Film Formation ◽

Electrochemical Studies

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Simulators of Thin Film Deposition for Silicon Device Processing

MRS Proceedings ◽

10.1557/proc-514-119 ◽

1998 ◽

Vol 514 ◽

Author(s):

G. H. Gilmer ◽

F. H. Baumann ◽

T. Diaz de la Rubia

Keyword(s):

First Principles ◽

Film Formation ◽

Level Set Methods ◽

Thin Film Deposition ◽

Film Deposition ◽

Tin Films ◽

Grain Structures ◽

Device Processing ◽

Wide Range ◽

Silicon Device

ABSTRACTWe discuss simulators of the deposition of metal films onto substrates containing vias and trenches. Our Monte Carlo simulations of Al are based on extensive first-principles and molecular dynamics (MD) data for atomic-level energetics and transport rates. We find that surface mobilities are highly anisotropic, and that this has a pronounced influence on film morphology. We have investigated the effects of faceting and grain boundary grooving on step coverage, together with the variation of morphology with deposition rate, temperature, and length scale. Mass transport across low index facets is extremely slow near equilibrium, and this can inhibit the smoothening of surfaces and the elimination of depressions during annealing. The MC model also predicts grain structures during polycrystalline film formation, and the generation of preferred crystallographic orientations (texture). We present MC simulations for a range of conditions, and provide comparisons with experiments on the sputter deposition of Al and TiN films. Results from the MC model are being incorporated into a continuum model based on level-set methods, and we expect that this will form the basis for a simulator that can efficiently explore a wide range of conditions.

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