[en] A deep band of {311} defects was created 520 nm below the silicon surface with a 350 keV Si implant followed by a cluster-forming rapid thermal anneal (800 C, 1000 s). Chemical etching was used to vary the depth to the surface of the {311}-defect band. Afterwards, the defect dissolution was investigated at 750 C for different times. Varying the depth in this fashion assures that only the depth and no other feature of the cluster distribution is changed. The {311} defects were analyzed by plan-view, transmission electron microscopy. We show that the dissolution time of the {311}-defect band varies linearly with depth, confirming that surface recombination controls the dissolution and is consistent with analogous observations of transient enhanced diffusion

[en] We have measured the evolution of the excess-vacancy region created by a 2 MeV, 10¹⁶/cm² Si implant in the silicon surface layer of silicon-on-insulator substrates. Free vacancy supersaturations were measured with Sb dopant diffusion markers during postimplant annealing at 700, 800, and 900 C, while vacancy clusters were detected by Au labeling. We demonstrate that a large free vacancy supersaturation exists for short times, during the very early stages of annealing between the surface and the buried oxide (1 μm below). Afterwards, the free vacancy concentration returns to equilibrium in the presence of vacancy clusters. These vacancy clusters form at low temperatures and are stable to high temperatures, i.e., they have a low formation energy and high binding energy

[en] Measurements of the binding energy (E_b) of vacancies to vacancy clusters formed in silicon following high-energy ion implantation are reported. Vacancy clusters were created by 2 MeV, 2 x 10¹⁵ cm^-2 dose Si implant and annealing. To prevent recombination of the excess vacancies (V^ex) with interstitials from the implant damage near the projected range (R_p), a Si-on-insulator substrate was used such that the R_p damage was separated from the V^ex by the buried oxide (BOX). Two V^ex regions were observed: one in the middle of the top Si layer (V₁^ex) and the other at the front Si/BOX interface (V₂^ex). The rates of vacancy evaporation were directly measured by Au labeling following thermal treatments at temperatures between 800 and 900 C for times ranging from 600 to 1800 s. The rate of vacancy evaporation from V₂^ex was observed to be greater than from V₁^ex. The binding energy of vacancies to clusters in the middle of the silicon top layer was 3.2±0.2 eV as determined from the kinetics for vacancy evaporation

[en] We report the first experimental evidence for the resonant excitation of coherent high-frequency acoustic phonons in semiconducting doping superstructures by far-infrared laser radiation. After a grating-coupled delta-doped silicon doping superlattice is illuminated with ∼1 kW/mm² nanosecond-pulsed 246 GHz laser radiation, a delayed nanosecond pulse is detected by a superconducting bolometer at a time corresponding to the appropriate time-of-flight for ballistic longitudinal acoustic phonons across the (100) silicon substrate. The absorbed phonon power density in the microbolometer is observed to be ∼10 μW/mm², in agreement with theory. The phonon pulse duration also matches the laser pulse duration. The absence of any delayed transverse acoustic phonon signal by the superconducting bolometer is particularly striking and implies there is little or no incoherent phonon generation occurring in the process.

[en] We have investigated dopant-defect interactions during ion implantation of silicon into silicon by monitoring the radiation-enhanced diffusion (RED) of Sb and B dopant diffusion markers. The RED of these dopant markers has been investigated as a function of implant temperature (25-400 deg. C), implant dose (10¹⁴-10¹⁶ cm^-2), and implant energy (2 MeV or 40 keV Si ions). Experimental results are interpreted with the aid of atomistic simulations that include detailed defect-defect and dopant-defect interactions. We demonstrate that RED of B and Sb occurs at lower temperatures than previously reported (below 100 deg. C and 200 deg. C, respectively) and the magnitude of this effect increases with implant temperature and dose. We also demonstrate that RED of these dopants is only measurable within the damage cascades of the implanted ions, i.e., there is no observable long-range diffusion of defects during implantation. Significant differences in dose, temperature, and depth dependence between B and Sb RED occur. Comparison of experimental and simulation results indicates that these differences are due to the diffusion mechanisms of the dopants. Simulations also demonstrate that the formation and dissolution of defect clusters during implantation plays a significant role in the observed temperature and dose dependencies