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Reduced metal contamination levels become ever more critical as ultralarge scale integrated device feature sizes shrink to 0.25 p.m. Wafers may be contaminated with metals during their manufacture, but metals are more likely to be introduced at the wafer surface during integrated circuit processing. During high-temperature processing steps, the surface contaminants diffuse rapidly into the wafer bulk. Because carrier lifetime and diffusion length are strongly affected by the presence of parts per trillion levels of electrically active metal-related defect centers in the bulk of the wafer, these properties can be used to detect the presence of metal contamination. Unfortunately, these techniques are sometimes misused and misinterpreted. The more common techniques, their benefits, and limitations on their interpretation are discussed. A unified taxonomy to describe carrier lifetime characteristics is also proposed.

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Materials Characterization by Electrical Methods 7 3.1. U Through MIPR FY76 167600366 (NBS Cost Center 4259560). # Code SP-23, through project order N0016475P070030 administered by Naval Weapons Support Center, Crane, Indiana (NBS Cost Center 4251533).

Measurements of the magnetoresistance, Hall, and planar Hall coefficients have been made on oriented single crystals of w-type germanium at 77° and 300°K. At 77 °K measurements made as a function of the magnetic field strength and of the angle between the current and the magnetic field are found to be in agreement with theoretical calculations based on an energy-independent mean free time TO which has the same form of anisotropy as the effective mass at the bottom of the conduction band. The value of ro is determined from previously described Hall measurements and the anisotropy factor K is determined from the high-field longitudinal magnetoresistance. K decreases from about 16 to about 12 or 13 as the electron density increases from about 5.4 X10 13 cm" 3 to about 5.2 X10 14 cm" 3 .At 300 °K measurements were made for selected orientations of current and field on samples whose resistivities varied from 0.016 to 8.9 ohm-cm. The usual low-field symmetry relations are

We report an international interlaboratory dual experiment to determine the calibration factor used to calculate the interstitial oxygen content of silicon from room‐temperature (300 K) infrared (IR) absorption measurements. We conducted round robins for both the infrared and the absolute measurements on the same or equivalent specimens. The calibration factor for computing the oxygen content of silicon in parts per million atomic (ppma) from a room‐temperature measurement of the absorption coefficient at 1107 cm−1 was determined to be 6.28±0.18 normalppma/cm−1 . The IR round robin showed a reproducibility on the order of 3%.

Hall measurements have been made on oriented single crystals of w-type germanium confirming the variations of the Hall coefficient with the direction and magnitude of the magnetic field, and with the direction of the current, which are predicted by theories based on the eight-ellipsoid model. Although other assumptions must be made to secure exact agreement, these measurements, when made under suitable conditions, can be explained by a theory assuming an energy-independent scattering time r. This type of measurement may be useful in determining symmetry properties of the energy surfaces near a band edge in other semiconductors.

Gold was diffused into arsenic-doped silicon slices with initial resistivity of 0.3 or 5 Ω·cm at temperatures between 850° and 1250°C for times sufficiently long that the gold concentration was essentially constant, except for a very thin surface region which had a much larger concentration. The gold concentration was determined by means of neutron activation analysis. It was found that the gold concentrations were lower than would be expected from published solubility data when diffusion occurred at temperatures below 1100°C. Several surface treatments were found to result in similar gold concentrations when an evaporated gold film was used as the source. The measured room-temperature resistivity was found to be in fair agreement with computations using accepted values for the various silicon parameters and the gold energy levels. Although refinements in the calculations and improved experimental techniques are both still necessary, it has been shown that the qualitative features of the model on which the calculations are based are certainly correct. It has also been shown that gold diffusions in silicon with a moderate dislocation density can be carried out satisfactorily in an oxidizing atmosphere.