Subsurface damage in silicon formed by ion implantation and the residual damage after annealing have been successfully evaluated by measuring the photo-acoustic displacement (PAD) induced by an intensity modulated pump beam. The PAD was detected by a laser interferometrie probe with a sensitivity of 0.1 picometers in a noncontact manner. A temperature rise within the subsurface damage due to a decrease in the thermal conductivity leads to significant thermal expansion and causes a displacement on the sample surface. Therefore, subsurface damage can be monitored by measuring the PAD. Experimental results for As+ and B+ implanted samples indicate that recrystallization of ion implant damage by annealing can be monitored by this technique. Samples of higher doses (>1014/cm2) have residual damage even after annealing at 800'C for 30 minutes. The results for high-energy (2MeV) implanted samples also show that the secondary defects after annealing, which are formed in a deep region a few microns under the surface, can be detected with high sensitivity.

The crystallization behaviour of Ni doped magnetron co-sputtered amorphous silicon thin films (MSP-a-Si(Ni)) has been investigated by means of near infrared-visible-ultraviolet (NIR-VIS-UV) transmission spectroscopy, transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). Using the change in optical transmission spectra of crystallized a-Si(Ni) thin films the crystallization kinetics is described. At the crystallization frontier a needle morphology of single crystals is observed with STEM, which is followed by solid state diffusion of nickel through the amorphous matrix. Using a long term thermal treatment we have studied the formation of expansed monocrystalline networks.

The dose rate dependence of 300 keV Si+ ion beam induced epitaxial crystallization (IBIEC) of a 200 nm thick amorphous silicon surface layer at 400°C is investigated in the ion dose rate range from 3 · 1010 up to 3 · 1013cm2s−1. The experimental results are compared with theoretical predictions from several models. Special emphasis is given to the influence of the depth distribution of the nuclear energy deposition on the growth process during both the experiment and the theoretical analysis. According to our experimental results the IBIEC rate is indirectly proportional to the fourth root of the dose rate. This is in excellent agreement with a point defect diffusion model of IBIEC considering pairwise defect annihilation.

The incorporation of Er into LiNbO3 is of great interest for fabricating waveguide lasers and amplifiers. We compare Er diffusion data with the results of Er implantation, performed at 3.6 MeV energy. Even after annealing for 4h at 1060°C, the resulting Er profiles display very good matching to the optical modes. The results of a theoretical gain estimate are presented.

Metal colloids in glasses can yield an enhanced (χ((3)) susceptibility which leads to an intensity dependent refractive index. Ion implantation is a convenient means of introducing the metal species. The host glass plays an important role in colloid formation. We have characterized Ag-colloid formation in various silicate glasses and, in addition, have studied the formation of colloids in Ag-doped phosphate glass as a function of N and H implantation. Some preliminary results for Cu-implanted glasses are presented.

The near surface regions of high purity silica glass discs, Spectrosil A, were modified by implantation with bismuth ions at 160 keV and room temperature. The glasses implanted with a nominal dose of 6×1016 Bi/cm2 at ∼5 μA/cm2 were subsequently bleached with a 5.0 eV KrF pulsed excimer laser. The laser had an average pulse duration of -20 ns and repetition rate of 10 Hz. It was found that the bleaching was dependent upon the power density of the laser for a constant total integrated energy. Ion backscattering and optical absorption measurements were made before and after laser irradiation. Large changes in optical density and depth distribution of the implanted ions were observed at power densities of ≥45 mJ/cm2-pulse. On the basis of our experimental results, the onset of the threshold for bleaching of silica glass implanted with 6×1016 Bi/cm2 at 160 keV and at room temperature is between 30 and 45 mJ/cm2-pulse.

This paper reviews recent developments of plasma immersion ion implantation (PHI) for semiconductor applications: ultra-shallow junction formation, microscopic conformai doping, metallization, and impurities gettering. We also discuss semiconductor processing issues with PHI: reactor design, wafer charging, surface deposition/etching., and secondary electron emission.

Degradation of arsenic implanted titanium suicide (TiSi2) thin films as a result of thermal processing for shallow junction formation is investigated. Significant arsenic diffusion from the suicide overlayer into the silicon substrate has been detected by Rutherford Backscattering Spectrometry at drive-in temperatures > 1050°C. Cross-sectional transmission electron micrographs have shown the suicide film become increasingly non-uniform as the thermal budget increases, ultimately leading to discontinuities forming in the suicide film. This observed degradation of the titanium suicide film is also supported by sheet resistance measurements which show the film to degrade significantly above a threshold thermal budget

The fabrication process of high current arsenic (As) ion implanted poly-silicon (Si) gate and source-drain (SD) electrode Si n-channel metal-oxide-semiconductor field-effect-transistor (MOSFET) was examined. Poly-Si film n-type doping was performed by using high current (typical current: 2mA) and relatively low acceleration voltage (40keV) As ion implantation technique (Lintott series 3). It was observed that high dose-As implanted poly-Si films as is show refractoriness against radical fluorine excited by microwave. Using GCA MANN4800 (m/c ID No.2, resist: OFPR) mask pattern printing technique, the high current As ion implantation technique and radical fluorine gas phase etching (Chemical dry etching: CDE) technique. the n-channel poly-Si gate (ps=∼L00ft/o) enhancement MOSFETs(ps-source-drain = =50n/o, SiO2 gate=380A) with off-leak-less were obtained on 3”Czochralski-grown 2Ωcm boron-doped p-type wafers (Osaka titanium). By the same process, a 8-bit single chip μ-processor with 26MHz full operation was performed.

We have demonstrated the high energy (MeV) electron beam irradiation effects on lateral solid phase epitaxy (L-SPE) of Si-on-insulator (SOI). Thinned samples were set on a hot stage in a 2 MeV electron microscope and L-SPE growth under 2 MeV electron irradiation conditions was monitored in-situ by using the same microscope. L-SPE growth rate for the irradiation dose of 1021 cm−2 was enhanced by about 1.5 times greater than that under unirradiated condition. For electron beam irradiation doses higher than about 1023 cm−2, L-SPE growth was suppressed. Displacement of Si atoms, contamination effect and ionization effect are discussed as causes for the growth rate retardation and enhancement of L-SPE by electron beam irradiation.

Optical and infrared reflection spectra for Bi implanted silica are reported as a function of dose and thermal annealing. A series of high purity silica samples were implanted with Bi ions at an energy of 350 KeV. Doses were 1 × 1016 and 1.0 × 1017ions/cm2 at 5μamps/cm2. The samples were subsequently thermally annealed at 400, 600 and 800 C. The optical absorption from 6.2 to 1.8 eV and infrared reflectance from 5000 to 450 cm”−1 were measured before and after annealing. Effects of thermal annealing are strongly dependent on Bi content.

Single crystal diamond has been implanted at 1 MeV with 2×1020 Ar/m2. Rutherford backscattering spectrometry in a channeled geometry revealed a broad amorphized region underlying a thin, partially crystalline layer. Raman spectroscopy disclosed modifications in the bonding characteristic of the appearance of non-diamond carbon. The complementary nature of the two analysis techniques is demonstrated. The Knoop hardness of the implanted diamond was reduced by implantation.

A TRIM code [1] has been modified to simulate a special technique, first described at the Spring 92 MRS Meeting [2], for in situ transmission electron microscope (TEM) experiments involving simultaneous ion irradiation, in which the resultant phenomena are observed as in a cross-section TEM specimen without further specimen preparation. Instead of ion-irradiating the film or foil specimen normal to the major surfaces and observing in plan view (i.e., in essentially the same direction), the specimen is irradiated edge-on (i.e., parallel to the major surfaces) and is observed normal to the depth direction of the irradiation. The results of calculations utilizing the modified TRIM code are presented for cases of 200 and 500 keV Co impinging onto the edge of Si films 200 and 600 nm thick. The limitations of the technique are discussed and the feasibility of experiments involving implantation of Co into Si and the formation of COSi2, which employ this technique, are briefly discussed.

In Plasma Source Ion Implantation (PSII), a target to be implanted is immersed in a weakly ionized plasma and pulsed to a high negative voltage. Ions in the plasma are accelerated toward the target and implanted in its surface, thereby modifying the properties of the surface. Experimental results reported in the literature have generally been for small targets. We present here the design of a large-scale PSII experiment being assembled Los Alamos National Laboratory, in which we plan to implant targets with surface areas exceeding 1 m2 to doses of up to 5 × 1017 cm−2. In presenting this design, we use Monte Carlo and particle-in-cell simulations to examine sheath expansion, implant current and dose, secondary electron emission, target sputtering, implant depth, and x-ray emission resulting from secondary electrons hitting the vacuum chamber wall.

Highly oriented pyrolytic graphite samples were irradiated with C+ ions at 35 keV in a direction normal to the basal plane and subsequently annealed up to 1373 K. Substantial surface topography changes were observed at fluences of 5×1018 ions/m2 and higher using scanning electron and atomic force microscopies. Intricate networks of surface cracks and ridges developed after high dose implantation. A systematic study of the irradiation effects was conducted using Raman spectroscopy. Microstructural changes in irradiated regions were first detected at a dose of 1×1017 ions/m2 through the appearance of the Raman D-line at ∼1360 cm−1. The intensity of this line increases while that of the Raman G-line at 1580 cm−1 decreases as the irradiation dose is increased or the irradiation temperature is decreased. After irradiation at 280K to a fluence of 5×1019 ions/m2 or higher the first order spectrum exhibits one single line at a wavelength intermediate between the D- and G-lines. Damage recovery upon thermal annealing depends not only on the initial damage state but also on the annealing temperature sequence. Samples irradiated to a damage level where two distinct Raman peaks are no longer resolvable exhibited upon direct annealing at a high temperature two distinct Raman lines. By contrast, pre-annealing these highly irradiated specimens at lower temperatures produced less pronounced changes in the Raman spectra. Pre-annealing appears to stabilize damage structures that are more resistant to high-temperature annealing than those induced by irradiation.

A model of radiation induced phase transformations in quartz using the old idea of Weissmann and Nakajama is developed. The kinetics of these phase transitions is described taking into account intermediate phase formation. A model of the final radiation induced metamict state of quartz is suggested. The metamict state consists of amorphized matrix SiO2+X, where x ≈0.15 (radioglass), in which pure silicon precipitates are included.

Mössbauer spectroscopy on the 9.4 keV transition in 83Kr is used to study inert gases in metals and semiconductors. An absorber was made by implanting 83Kr at 110 keV in Al foils to a total dose of 1.7· 1016 Kr cm−2, leading to the formation of small precipitates (bubbles). Spectra on the as-implanted sample were taken as a function of temperature for three 83RbI sources which differ in line shape due to a different water content. A model is presented to extract the absorber parameters from the spectra in a consistent way, in spite of the different sources used. The spectra of Kr bubbles in Al produced by high dose implantation show two components: a single line from Kr inside the bubble and a quadrupole split component from Kr at the Kr-Al interface. The total absorption area could be fitted very well assuming a simple Debye model, yielding a Debye temperature of ΘDT = 101(2) K. For the individual components we obtained Debye temperatures of ΘDQ = 98(6) K and ΘDS = 90(10) K. The isomer shift of the bulk fraction is significantly larger than that of a solid Kr layer at ambient pressure, reflecting the fact that the s-density increases under compression. The size of the precipitates can be estimated to be 1.5–1.8 nm. Thin KrSi films, produced by Kr plasma sputter deposition, were characterized using cross-sectional X-ray analysis. The results clearly show two different layers. Presumably, the film grows at first as c-Si with a low Kr concentration, but after having reached a certain critical thickness, further growth proceeds as a-Si with a high Kr concentration. For Mössbauer spectroscopy an absorber of 83KrSi was made by plasma deposition on an Al foil. The spectra can be fitted with a single line and a quadrupole component, both with isomer shifts much larger than found in the case of small Kr bubbles in Al. No change in the total absorbed area was observed from 4.2 to 200 K indicating a lower limit of 250 k for the Debye temperature. Both observations indicate that the Kr resides in very small clusters.

Cross-sectional transmission electron microscopy was used to study diffusion-induced grain boundary migration (DIGM) in irradiated and annealed Au/Cu bilayers. Using this technique, in combination with small probe X-ray energy dispersive spectroscopy, DIGM alloyed zones in Au were identified in an irradiated sample.

The effects of implantation temperature and target composition on the depth distribution of the implanted species were systematically investigated in the present work. Au+ ions were implanted at 300 keV into polycrystalline Ni-Be and Ni-Si alloys at temperatures between 25 and 700 °C to a dose of 1016 cm−2. The depth distributions of Au were analyzed with RBS using He+ at both 1.7 and 3.0 MeV, and those of the other alloying elements by SIMS. Theoretical modeling of compositional redistribution during implantation at elevated temperatures was also carried out with the aid of a comprehensive kinetic model. The analysis indicated that below ∼250 °C, the primary controlling processes were preferential sputtering and displacement mixing, while between 250 and 600 °C radiation-induced segregation was dominant. Above 600 °C, thermal-diffusion effects were most important. A systematic fitting of model calculations to experimental measurements provided values for various defect migration and formation parameters.

Computer simulations in conjunction with TEM experiments have been used to test the different models usually adopted in the literature to explain the formation of “End Of Range”(EOR) defects which appear after annealing of preamorphized silicon layers. Only one survives careful experimental investigations involving Si+, Ge+, Sn+ amorphization at RT and LNT. The “excess-interstitial” model appears relevant at least for a semi-quantitative explanation of the source of point-defects which after recombination and agglomeration, lead to the formation of these defects. This model may be used for the numerical optimization of conditions for the production of high performances ullra-shallow junctions.