I/F Noise Measurements in Al-Si, Al-Si-V and Al-Si-V-Pd Alloy Films

ABSTRACTThe electromigration lifetime of Al-Si (1 at.% Si) can be greatly increased by alloying with V and Pd (0.1 at.% V, 0.1 at.% Pd). This study reports on l/fα (α≈l) noise measurements in Al-Si, Al-Si-V and Al-Si-V-Pd alloy films. Samples were prepared by direct current (DC) sputtering, e-beam lithography and reactive-ion etching. The samples were annealed at 450 °C for 30 min and were not passivated. Test line dimensions were 800μm×l.2μm×0.5μm. 1/f noise was measured by a high-resolution alternating current (AC) bridge technique, which ensured that no electromigration occurred during the measurements. The sample-to-sample variation in normalized 1/f noise intensity for Al-Si, Al-Si-V and, Al-Si-V-Pd, measured at room temperature, was less than 10%. The smallest noise intensities were observed in the Al-Si-V-Pd films. The temperature dependence of the 1/f noise of Al-Si films shows a maximum at 338 K allowing the determination of the activation energy of the noise generating process (Ea = 0.75 eV). Above 400 K the resistance of the samples became unstable preventing reliable noise measurements. The instabilities were probably caused by the dissolution of very small Si precipitates (<10 nm). This is important information because the dissolution will also take place during electromigration lifetime experiments.

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Comparison Between I/F Noise, High-Resolution Resistometric, and Lifetime Electromigration Studies of AL and AL(SI)

MRS Proceedings ◽

10.1557/proc-309-307 ◽

1993 ◽

Vol 309 ◽

Cited By ~ 5

Author(s):

J.R. Kraayeveld ◽

A.H. Verbruggen ◽

S. Radelaar

Keyword(s):

Thin Films ◽

High Resolution ◽

Room Temperature ◽

Activation Energies ◽

Lifetime Measurements ◽

Noise Measurements ◽

Electromigration Lifetime ◽

Local Disorder ◽

Dc Current

AbstractTo compare the results obtained by 1/f noise, high-resolution resistance and electromigration lifetime measurements, the effect of annealing at 400 °C in forming gas of Al and AI(Si) thin films has been studied. All samples of a given composition have been fabricated simultaneously. Upon annealing, the 1/f noise measured at room temperature decreases by a factor of two whereas the lifetime increases by a factor 3 to 6. The activation energies derived from the 1/f noise and the high-resolution resistance measurements during and after stressing with a DC current are closely correlated and compare well to values reported for lifetime measurements. Comparing the data of the different experiments suggest that the lifetime experiments predominantly probe the presence of weak spots in the films whereas the noise measurements respond more to local disorder.

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Interactions Between Al and Cr Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100093158 ◽

1976 ◽

Vol 34 ◽

pp. 638-639

Author(s):

R. M. Anderson ◽

T. M. Reith ◽

M. J. Sullivan ◽

E. K. Brandis

Keyword(s):

Thin Films ◽

Room Temperature ◽

Vacuum System ◽

Processing Temperature ◽

Diffusion Couples ◽

Electronic Circuits ◽

Intermetallic Formation ◽

Si Substrates ◽

Aluminum Silicon

Thin films of aluminum or aluminum-silicon can be used in conjunction with thin films of chromium in integrated electronic circuits. For some applications, these films exhibit undesirable reactions; in particular, intermetallic formation below 500 C must be inhibited or prevented. The Al films, being the principal current carriers in interconnective metal applications, are usually much thicker than the Cr; so one might expect Al-rich intermetallics to form when the processing temperature goes out of control. Unfortunately, the JCPDS and the literature do not contain enough data on the Al-rich phases CrAl7 and Cr2Al11, and the determination of these data was a secondary aim of this work.To define a matrix of Cr-Al diffusion couples, Cr-Al films were deposited with two sets of variables: Al or Al-Si, and broken vacuum or single pumpdown. All films were deposited on 2-1/4-inch thermally oxidized Si substrates. A 500-Å layer of Cr was deposited at 120 Å/min on substrates at room temperature, in a vacuum system that had been pumped to 2 x 10-6 Torr. Then, with or without vacuum break, a 1000-Å layer of Al or Al-Si was deposited at 35 Å/s, with the substrates still at room temperature.

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STEM and ELS Observation of Early Oxide Formation on the Surface of Cr Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001768 ◽

1980 ◽

Vol 38 ◽

pp. 412-413

Author(s):

Fumio Watari ◽

J. M. Cowley

Keyword(s):

Thin Films ◽

Optical System ◽

Room Temperature ◽

Oxide Formation ◽

Initial Nucleation ◽

Diffraction Patterns ◽

Relationship Of ◽

Multiple Twinning ◽

Moderately High Temperature

STEM coupled with the optical system was used for the investigation of the early oxidation on the surface of Cr. Cr thin films (30 – 1000Å) were prepared by evaporation onto the polished or air-cleaved NaCl substrates at room temperature and 45°C in a vacuum of 10−6 Torr with an evaporation speed 0.3Å/sec. Rather thick specimens (200 – 1000Å) with various preferred orientations were used for the investigation of the oxidation at moderately high temperature (600 − 1100°C). Selected area diffraction patterns in these specimens are usually very much complicated by the existence of the different kinds of oxides and their multiple twinning. The determination of the epitaxial orientation relationship of the oxides formed on the Cr surface was made possible by intensive use of the optical system and microdiffraction techniques. Prior to the formation of the known rhombohedral Cr2O3, a thin spinel oxide, probably analogous to γ -Al203 or γ -Fe203, was formed. Fig. 1a shows the distinct epitaxial growth of the spinel (001) as well as the rhombohedral (125) on the well-oriented Cr(001) surface. In the case of the Cr specimen with the (001) preferred orientation (Fig. 1b), the rings explainable by spinel structure appeared as well as the well defined epitaxial spots of the spinel (001). The microdif fraction from 20A areas (Fig. 2a) clearly shows the same pattern as Fig. Ia with the weaker oxide spots among the more intense Cr spots, indicating that the thickness of the oxide is much less than that of Cr. The rhombohedral Cr2O3 was nucleated preferably at the Cr(011) sites provided by the polycrystalline nature of the present specimens with the relation Cr2O3 (001)//Cr(011), and by further oxidation it grew into full coverage of the rest of the Cr surface with the orientation determined by the initial nucleation.

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A New Method for Direct Determination of the Recoilless Fraction with Application to Magnetic Nanoparticles

MRS Proceedings ◽

10.1557/proc-721-e3.7 ◽

2002 ◽

Vol 721 ◽

Author(s):

Monica Sorescu

Keyword(s):

Room Temperature ◽

Average Particle Size ◽

Direct Determination ◽

Average Particle ◽

Lattice Method ◽

Recoilless Fraction ◽

Single Room ◽

Magnetite Particles ◽

Physical Mixtures

AbstractWe propose a two-lattice method for direct determination of the recoilless fraction using a single room-temperature transmission Mössbauer measurement. The method is first demonstrated for the case of iron and metallic glass two-foil system and is next generalized for the case of physical mixtures of two powders. We further apply this method to determine the recoilless fraction of hematite and magnetite particles. Finally, we provide direct measurement of the recoilless fraction in nanohematite and nanomagnetite with an average particle size of 19 nm.

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Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

10.26434/chemrxiv.11345063.v2 ◽

2020 ◽

Author(s):

Keishiro Yamashita ◽

Kazuki Komatsu ◽

Hiroyuki Kagi

Keyword(s):

Crystal Structure ◽

High Pressure ◽

Crystal Growth ◽

Single Crystal ◽

Room Temperature ◽

Growth Technique ◽

Salt Hydrate ◽

X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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