Si wafers were preamorphized by either Si or Ge ions at temperatures between 5 and 40°C. The diffusion of low energy 4 keV B implants into the preamorphized Si was studied in order to monitor the flux of interstitials from the end of range EOR region toward the surface. Transient enhanced diffusion TED in the regrown silicon was observed for all implants. Increasing the implantation temperature of the Si implant by as little as 15°C can result in a marked decrease in the magnitude of the interstitial flux flowing from the EOR region toward the surface. This sensitivity to implant temperature appears to be even greater for Ge implants. In order to better understand this effect, detailed transmission electron microscopy TEM studies were conducted. As-implanted cross-sectional TEM micrographs indicate a measurable decrease in the thickness of the amorphous layer up to 300 Å occurs when the implantation temperature increases from 5 to 40°C as a result of ion beam induced epitaxial recrystallization. Upon 800°C annealing, two types of defects are observed in the EOR region: 311 defects and dislocation loops. The 311 defects are unstable and the comparison of secondary ion mass spectroscopy and TEM data for annealed samples indicating the dissolution of these 311 defects is at least one of the sources of interstitials for TED in the regrown Si at 800°C. The EOR dislocation loops are stable for the annealing conditions used in this study 800°C for 15 min and there appears to be an exponential dependence of the TED that occurs in regrown Si on the density of the EOR dislocation loops.

(001) CZ silicon wafers were implanted with As+ at 100 keV to a dose of 1×1015/cm2 in order to produce a continuous amorphous layer to a depth of about 120 nm. Furthermore, the implant condition was such that the peak arsenic concentration was below the arsenic clustering threshold. Subsequently, a second As+ or Ge+ implant was performed at 30 keV to doses of 2×1015/cm2, 5×1015/cm2 and 1×1016/cm2, respectively, into the as-implanted samples. All of the samples were annealed at 800 °C for 1 h. The second implant was designed to be contained within the amorphous region created by the initial implant. The second As+ implant was also designed to provide the additional arsenic needed to exceed the critical concentration for clustering at the projected range. Of the three samples with the dual As+ implant the clustering threshold was exceeded for the two lower doses while the SiAs precipitation threshold was exceeded at the highest dose. In the case of the dual As+/Ge+ implants the clustering and precipitation thresholds were not reached. Since arsenic and germanium are similar in mass the extent of damage created by these implants would be comparable. The implanted and annealed specimens were analyzed using secondary ion mass spectroscopy and transmission electron microscopy. The difference in the defect evolution and the transient-enhanced diffusion of arsenic beyond the end-of-range region between the As+ and Ge+ implanted and annealed samples was used to isolate the effects of arsenic clustering and precipitation. The results showed that point defects induced during clustering and/or precipitation did not contribute to the enhanced diffusion of arsenic although these defects did coalesce to form extended defects at the projected range. However, damage beyond the end-of-range region did cause enhanced diffusion of arsenic.

We determined the phase stability limits of Bi2Sr2Ca1Cu2O8+δ and Bi2Sr2Ca2Cu3O10+δ in the temperature range 650–880 °C using a solid-state electrochemical technique. These phases decompose by incongruent melting above ∼790 °C, whereas they decompose by a solid-state reaction at lower temperatures. The solid-state decomposition reaction is reversible for Bi2Sr2Ca1Cu2O8+δ, but not for Bi2Sr2Ca2Cu3O10+δ.

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Transient enhanced diffusion of boron in preamorphized and subsequently regrown Si was studied by secondary ion mass spectrometry SIMS and transmission electron microscopy TEM. A comparison of 4 keV, 1 10 14 /cm 2 boron implants into crystalline and Ge preamorphized silicon was undertaken. Upon annealing the B implant into crystalline material exhibited the well-known transient enhanced diffusion TED. In this case the peak of the boron distribution was relatively immobile and only B in the tail showed TED. In the second set of samples, the surface was first preamorphized by a 180 keV, 110 15 /cm 2 Ge implant which produced an amorphous layer 2300 Å deep, which then was implanted with boron. After implantation the tail of the B distribution extended to only 700 Å. Upon annealing, TED of the boron in the regrown Si was also observed, but the diffusion profile was very different. In this case the peak showed no clustering, so the entire profile diffused. The time for the TED to decay was around 15 min at 800°C. TEM results indicate that the 311 defects in the end of range damage finish dissolving between 10 and 60 min at 800°C. These results indicate that for these Ge preamorphization conditions, not only do the end of range defects not block the flow of interstitials into the regrown silicon, the 311 defects in the end of range damage act as the source of interstitials. In addition, boron does not appear to cluster in regrown silicon.