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A number of commonly employed experimental methods used to determine the μτ product in the semiconductor CdZnTe were investigated. The objective was to determine possible differences in results inherent in the techniques. A pixelated and two planar devices were studied using various distinct methods together with different excitation sources and amplifier shaping times. Variations in the results up to a factor of 5 were found. Variations due to shaping times, particle type, and energy were evident. [ABSTRACT FROM AUTHOR]

Positron annihilation lifetime spectroscopy (PALS) was used to study the nanoporous structure of spin-on and chemical vapor deposited low dielectric constant (low-k) films. Orthopositronium (o-Ps) lifetimes provided information on pore size, open and closed porosities, and depth profile of pore sizes in low-k films. In combination with three-photon (3γ) yield obtained from positron annihilation spectroscopy, the formation, diffusion, and annihilation of o-Ps are correlated with the chemical composition of matrix. The weak interaction between o-Ps and matrix with the network structure composed of Si, C, O, and H atoms allows us to extract nanoporous information from o-Ps lifetime and 3γ yield. The effects of pore generator (porogen) chemistry, thin film capping, plasma treatment, and positron radiation on nanoporous structure in several low-k films were demonstrated, which provided the information on process compatibility of low-k films. Unsolved issues related with Ps probing nano-structure of porous low-k films are summarized. [ABSTRACT FROM AUTHOR]

We investigated a red to yellow color change observed in α-HgI[sub 2] when cooled below 150 K. A phase transformation to β-HgI[sub 2], which has a yellow color, was ruled out by a variable temperature x-ray diffraction study. Instead the color change at cryogenic temperatures is caused by a shift in the transmission edge to shorter wavelengths which we attribute to a widening band gap at low temperatures. Using optical transmission spectroscopy the width of the band gap was measured between 10 and 330 K. At room temperature the gap was 2.11 ± 0.03 eV, which is significantly smaller than the most recently published values of ∼2.3 eV. This smaller band gap was further verified by measuring the thermoelectric current at elevated temperatures. [ABSTRACT FROM AUTHOR]

Presents information on a study which employed a Monte Carlo calculation to examine the behavior of the implantation profiles and other quantities in the energy range from 25 electronvolt to thermal energies. Procedure for the Monte Carlo method; Effects of the scattering mechanisms in the proposed model; Validation of the power-law description of the mean depth; Implantation profiles.

Provides information on a study that described positron annihilation studies of silicon dioxide/silicon (100) structures having 100-nautical mile-thick oxide grown by plasma enhanced chemical vapor deposition. Use of a normalized shape parameter; Manner of demonstrating activation and passivation of interface states by atomic hydrogen; Reason for the growth in the field of positron annihilation studies.

Demonstrates how positron annihilation spectroscopy (PAS) can be used as a nondestructive probe to examine defects in silicon (Si)-based structures. Analysis of the activation energy for hydrogen detrapping; Description of the use of PAS in compound semiconductor systems; Characterization of defects generated in bulk Si at various processing stages; Information on PAS.

Provides information on a study that performed continuous and time-gated photoluminescence of Si[sup+] implanted SiO[sub2] layers from the as-implanted samples. Experimental procedure; Results and discussion on the study; Conclusions.

Compares Cu(In,Ga)Se[sub2] device efficiency with junction depth and interfacial structure. Technique which examines changes in Doppler broadening of the annihilation gamma rays that originate from various depths of a test material; X-ray photoemission spectroscopy compositional analysis of the near surface region of the CuInSe[sub2] and Cu(In,Ga)Se[sub2] polycrystalline thin films; Factor used to determine chemical bonding differences between the surface and the bulk.

Deals with a study which investigated open-volume defects introduced in silicon (100) crystals during fluorine implantation by variable-energy positron beam depth profiling. Experimental details; Results and discussion.

Examines vacancy-type defects produced by implantation of megaelectronvolt doses of silicon ions at room temperature. Use of depth-resolved positron annihilation spectroscopy; Findings of the positron annihilation measurements; Measurements of defect accumulation as a function of dose.

Presents a study that investigated positron annihilation spectroscopy as a method to examine the properties of interface traps in metal-oxide semiconductors (MOS). Analysis of the behavior of the interface traps as a function of gate bias using positrons; Details on a proposed model to explain the positron annihilation spectra from the interface region of a MOS capacitor; Background on MOS technology.

Provides information on a summary of the results of a positron study of SiO[sub2]-Silicon and metal-oxide semiconductor structures. Details on the experiment; Results and discussion; Conclusion.

Presents a study which examined centroid shifts of positron annihilation spectra from the electric field-induced depleted regions of metal oxide semiconductor structures. Explanation of centroid shift measurement as a function of the positron beam energy; Experimental methods; Results and discussion.

Reports on the use of positron annihilation to investigate how the film microstructure influenced the trapping in iron films. Sample preparation and (D) deuterium charging; D contents of the films; Effect of annealing; Effect of polycrystallinity.