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The advantages of time of flight method enable it to be widely used on stationary reactors. In this study, we reported several typical applications of time of flight method on the China Advanced Research Reactor (CARR). First, a new solution is designed to measure the beam characteristics including wavelengths, wavelength resolution rates and intensities of HOPG(002) monochromator for the unfiltered and filtered cases. Second, the changes in neutron wavelength spectra on the cross section of curved neutron guide CNGB end were examined and studied. It can be concluded that evident shape changes between neutron wavelength spectra along horizontal direction are mainly caused by the horizontal curving of curved neutron guide and dips at other wavelengths apart from 4 A are mainly caused by small radius of curvature of curved neutron guide. Third, based on neutron velocity selector of small angle neutron scattering instrument at CARR, a calibration instrument is designed, and calibration experiments are conducted and simulated. The results indicate that the discrepancy between the experimental wavelength resolution rate and the theoretical one is caused by beam divergence linked with the critical reflection angle of neutron guide coating and the difference between experimental wavelength and the theoretical one is caused by the shape change of source neutron wavelength spectrum. These findings are reported here for the first time.

The quality of physical vapor deposition (PVD) grown barrier/seed interface in Cu interconnect metallization was significantly improved by enhancing Cu nucleation on the Ta barrier surface. This was accomplished through filtering of nonenergetic species from the deposition flux, increasing the fraction of Cu ions, improving metal ion flux uniformity, and minimizing gas ion bombardment of the growing film. The self-sputtering ability of Cu was combined with a magnetically confined high-density plasma in the Novellus hollow cathode magnetron (HCM®) PVD source. Spatial profiles of plasma density and temperature, as well as ion flux, metal ion fraction, and ion energy, were measured by planar Langmuir probes, quartz crystal microbalances, and gridded energy analyzers, all located at the wafer level. Multiple criteria, such as seed step coverage and roughness, the seed layer’s resistance to agglomeration, and its stability in the plating bath, have been used to evaluate interface quality. As a result, a new an...

To meet the stringent requirements of interconnect metallization for sub-32 nm technologies, an unprecedented level of flux and energy control of film forming species has become necessary to further advance ionized physical vapor deposition technology. Such technology development mandates improvements in methods to quantify the metal ion fraction, the gas∕metal ion ratio, and the associated ion energies in the total ion flux to the substrate. In this work, a novel method combining planar Langmuir probes, quartz crystal microbalance (QCM), and gridded energy analyzer (GEA) custom instrumentation is developed to estimate the plasma density and temperature as well as to measure the metal ion fraction and ion energy. The measurements were conducted in a Novellus Systems, Inc. Hollow Cathode Magnetron (HCM(TM)) physical vapor deposition source used for deposition of Cu seed layer for 65-130 nm technology nodes. The gridded energy analyzer was employed to measure ion flux and ion energy, which was compared to the collocated planar Langmuir probe data. The total ion-to-metal neutral ratio was determined by the QCM combined with GEA. The data collection technique and the corresponding analysis are discussed. The effect of concurrent resputtering during the deposition process on film thickness profile is also discussed.

The growth of plasma-enhanced atomic layer deposition (PEALD) grown copper films appropriate for nanoscale electronics applications is reported. Self-limiting PEALD copper growth behavior, employing copper(II) acetylacetonate and atomic hydrogen as reactants, was observed. Deposition of continuous layers as thin as 10 nm was achieved on TaN, Ru, and SiO2 substrates in a temperature range between 85 and 135 °C. A copper purity greater than 95 at. %, as measured by Auger electron spectroscopy, was observed. For a 30 nm thick film, PEALD copper resistivity was 5.3 μΩ cm on TaN and 8.8 μΩ cm on Ru. Conformal depositions have been achieved over high aspect ratio (∼5:1) structures.