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The microstructure of silica glasses which have been implanted with 1.0 MeV O and 1.8 MeV Cu ions and subsequently annealed at 1000°C are examined by transmission electron microscopy (TEM). It is found that a high density of single crystal nanoparticles are formed in a buried layer around 0.8–1.7 μm in depth. In the case of the Cu-implanted sample, only single crystal Cu nanoparticles are observed. When the ratio of the implanted O to Cu ion is 0.5:1, single crystalline nanoparticles of Cu2O are observed at a deeper part of the buried layer, associated with the projected range of the implanted O ions. As the O ion dose increases up to a ratio of O to Cu like 1:1, single crystals of CuO are formed in the buried layer. The depth profile of Cu and the size distribution of the nanoparticles are affected by the O ion-implantation.

Titanium dioxide (TiO 2 ) films prepared by a sol-gel method were irradiated with 0.5 MeV V, Ti and 1.8 MeV Au ions and subsequently annealed at approximately 480°C. After the implantation and thermal annealing, the microstructure and the optical properties of the TiO 2 films were studied by Rutherford backscattering spectrometry (RBS), optical absorption and glancing angle X-ray diffraction measurements. It was found that the distribution of the implanted metal was slightly changed after annealing. The absorption edge of the films also slightly shifted toward the longer wavelength side. The films were composed of anatase and rutile phases. The anatase phase was reduced by ion implantation.

We have examined the change of electric conduction of silicon nitride induced by MeV Si ion implantation. 2 MeV Si + ions were implanted at the doses from 1×10 14 to 3×10 17 ions/cm 2 in 12 steps, by measuring the resistance using dc-constant voltage method between two deposited Mo thin films as electrodes on the sample. Temperature during implantation was 370–530 or 600 K without or with heater. Up to the dose of 2×10 16 or 8×10 15 ions/cm 2 for without or with heater, sheet resistance was larger than 10 9 Ω/□. The resistance decreased dramatically with increasing dose and it became less than 10 5 Ω/□ at doses over 1×10 17 ions/cm 2 . Saturation of conductivity over the dose of 1×10 17 ions/cm 2 was clear with the heater. Temperature dependence of conductivity indicates that the conductor is as semiconductor. After annealing up to 1000 K, the conductivity increased; however, it decreased beyond 1150 K and it became almost non-conductive at 1500 K. The electric conduction induced by Si ion implantation occurs via a variable-range hopping process and closely related to defects and their behavior.

Recently a pulsed inductively coupled plasma source suitable for plasma-based ion implantation has been developed. The use of a pulsed plasma for plasma source ion implantation (PSII) processing takes advantage of the fact that a high-density plasma can be obtained with low average power because of the shortening of the plasma ignition time. A time resolved plasma density and the spatial profiles of the pulsed inductive RF plasma for the PSII method were measured. Under the optimal condition of the pulsed plasma, DLC thin films were successfully deposited on silicon substrates using Ar, CH 4 and C 7 H 8 gases, and the effects of the implantation voltage on the hydrogen concentration and the deposition rate of DLC coating were measured in the range of 5–20 kV. It was found that the deposition rate decreased with increasing implantation voltage and the hydrogen concentration was within 15–22 at.%.

In order to study the behavior of implanted nitrogen into Zr/carbon and Si/carbon bilayers, depth profiles of 15N and 14N were measured using the nuclear reaction of 15N(p,αγ)12C and 14N(3He,α)13N, respectively. The measured depth profiles were compared with the calculated profiles obtained by Monte Carlo simulation using dynamic-SASAMAL assuming a 25 at.% saturation for nitrogen concentration in carbon. Single 15N implantation and alternate implantation of 15N and 14N were performed at RT and at 700°C, with and without annealing. For depth profiling of the other elements, RBS was used and the chemical state was analyzed by XPS with Ar sputtering. The depth profiles of implanted nitrogen in Zr (60 nm)/glassy carbon (GC) showed nitrogen diffusion from the GC layer to the upper Zr layer. The depth profiles of the implanted nitrogen in Si/GC and Si/diamond-like carbon (DLC) agreed with the SASAMAL results assuming 40 at.% saturation for N in Si. The depth profile of 15N (1 × 1017 cm−2) which was implanted into Si/DLC after 14N (4 × 1017 cm−2) implantation did not agree with the calculated result but were almost the same as the profiles of 14N (4 × 1017 cm−2) except for the concentration level. And half of the 15N were lost during the annealing at 700°C, 1 h, keeping the same depth profile. The annealing behavior of the first implanted 14N was the same as the 15N.

Efforts have been dedicated to the formation of carbon nitride, a super-hard material, by many researchers. However, the nitrogen to carbon ratio obtained by high dose nitrogen implantation into carbon is quite limited by nitrogen diffusion towards the surface during the implantation. In order to study the behavior of implanted nitrogen, dynamic Monte Carlo simulations were carried out using the dynamic-SASAMAL code for nitrogen implantation into carbon, Si/C and Zr/C bilayers with energies of 25, 50 and 150 keV at doses of 5 × 1016 to 1018 cm−2. The calculated results were compared with the experimental results obtained by NRA, RBS, and XPS for RT implantation with and without annealing, and for 700°C implantation. For the RT implantation at a low fluence up to 1 × 1017 ions/cm−2, the measured NRA profile agreed well with the calculated result and almost all implanted nitrogen retained in the target. But diffusion began around 2 × 1017 cm−2 and the maximum concentration did not reach the calculated value. And the nitrogen concentration saturated at 25 at.%, and retained doses were much lower than the calculated values in all systems. The atomic ion mixing and the sputtered losses obtained by the calculation and the experiment were agreed very well.

Microstructure of the titanium hydride (deutende) films prepared by rf reactive sputtering with Ar and H2 (or D2) gases were examined by X-ray diffraction measurements, scanning electron microscopy, Rutherford backscattering spectrometry and elastic recoil detection analysis. In addition, their optical measurements were also carried out in visible and infra-red regions. It was found that the hep Ti structure (α-TiHx) was mainly formed at high rf power. With decreasing rf power, however, the fcc CaF2 structure (δ-TiHx) was obtained. The films have a smooth surface at a short time of deposition for 1–10 min, and these films are used for optical measurements. The films show wide absorption over visible and infra-red regions, although the films include a large amount of O atoms, which may suggest the presence of the amorphous titanium oxide phase.

Diamond-like carbon (DLC) films prepared by an ion plating method using C 6 H 6 plasma were implanted with 25 keV nitrogen 15 N ions to a total dose of 5 × 10 17 ions/cm 2 at temperatures up to 900°C. The atomic concentration of the implanted layer was measured by nuclear reaction analysis (NRA) and elastic recoil detection (ERD). Macro- and micro-tribological properties of the implanted layer were examined by a reciprocating tribotester and atomic force microscope (AFM), respectively. It was found that the nitrogen concentration in DLC films implanted at RT saturated at 23%, and a groove was formed by micro-wear on the surface at a low load of 150 nN, whereas the groove was not formed on the unimplanted surface. At 900°C implantation, the maximum concentration of nitrogen was 10%, and nitrogen implanted at high dose diffused into the substrate.

Silicon carbide was implanted with 50 keV nitrogen at elevated temperature up to 1100°C in order to form a composite of SiC and Si 3 N 4 . The depth profiles, the chemical state of the elements and the structure of the implanted surface were measured using Rutherford backscattering (RBS), nuclear resonance analysis (NRA), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and glancing angle X-ray diffraction (G-XRD). With increasing nitrogen fluence a replacement of carbon by nitrogen took place and β-Si 3 N 4 crystallites were formed on β-SiC surface at 1100°C, and the maximum concentration and halfwidth of the nitrogen profile implanted at 1100°C decreased in comparison with those implanted at

For nitrogen implantation into several kinds of metals (Al, Ti, V, Fe, Co, Ni, Zr, Nb, Mo, Ta, Hf, W) with a dose up to 2×10 18 ions cm −2 , dose dependence of the nitrogen depth profile, retained nitrogen dose and sputtering yield were calculated by Monte Carlo simulation using the dynamic SASAMAL code for the energy rage of 1 keV to 1 MeV. The calculated results were compared with the experimental results obtained by a resonant nuclear reaction analysis using 15 N(p, αγ ) 12 C reaction. In the simulation, it was assumed that the nitrogen concentration could not exceed that of saturated nitride phase and that the excess nitrogen migrated towards the surface depending on the radiation damage. The depth dependence of the chemical state measured by XPS and the crystalline structure of the surface layer obtained by a glancing angle XRD are also presented for Zr implanted with 50 keV nitrogen at room temperature and at high temperature or with post implantation annealing. The depth dependence of microhardness was also measured by an ultra-micro indentation tester. In order to find the method to overcome the limited thickness and the severe radiation damage problem at high dose implantation necessary for the saturation, the nitrogen depth profiles for an energy scanning implantation with a uniform and a non-uniform energy distribution were calculated and compared with those of monoenergetic implantation.

Optical and structural changes of sapphire(0001) substrates implanted with Ti ions or with Ti and 0 ions and subjected to thermal annealing, are examined by optical absorption, RBS-channeling and XRD measurements. The transmittance of the co-implanted sample was larger than that of the Ti-implanted sample. After annealing at 1000 °C, rutile-type TiO 2 microcrystals with (200) orientation were formed in the co-implanted sample of Ti and O ions. Furthermore, a broad optical absorption at 220–340 nm in the co-implanted sample was increased after the annealing. This was possibly due to the formation of TiO2 microcrystals in the sapphire substrate. In contrast to this result, no evidence of the formation of titanium oxide in a crystal structure was obtained for the Ti-implanted sample after the annealing.

To study the property changes of Zr induced by high dose nitrogen implantation at RT and at 600°C, the depth profiles of nanohardness were measured and compared with those of nitrogen concentration and chemical states of nitride phase. The implantation was performed with 100 keV N + 2 ions and doses from I × 10 16 to I ×10 18 N/cm 2 . The nanohardness was measured by an ultra micro indentation tester. The nitrogen depth profile was measured by NRA using 15 N(α,γ) 12 C reaction and RBS, Depth dependence of chemical state was measured by XPS combined with Ar sputtering. Dose and temperature dependence of the crystalline structure were measured by glancing angle XRD. There was no difference in the XPS spectra between RT and 600°C, and the spectra indicated that ZrN was formed at the depth where nitrogen existed. Since the heat of formation of ZrN is rather high, the depth profile of the implanted nitrogen in Zr was hardly changed up to 600°C. But the XRD patterns showed the increase of crystalline nitride phase with the increase of implantation and annealing temperatures. From the dose and temperature dependence of nanohardness profile, the hardness increase by low dose implantation around 1 × 10 17 ions/cm 2 at both RT and 600 C is attributed to point defects and interstitial hardening and the increase by high dose implantation above a dose around 5 x 10 17 ions/cm 2 at 600 C is attributed to the formation of ZrN phase.

Thin films of TiO 2 prepared by a sol–gel method were irradiated with 100 keV Ar ions. A bilayer (Mo/TiO 2 ) and multilayers (TiO 2 /Mo,Cr,Ag/TiO 2 ) of the thin metal films and TiO 2 were used. After the irradiation, concentration profiles and the structure of the surface layer were studied by Rutherford backscattering spectroscopy (RBS), X-ray photoelectron spectroscopy (XPS) and glancing angle X-ray diffraction (G-XRD). It was found that a ballistic mixing was predominant in the redistribution of Mo and Cr atoms embedded in TiO 2 , and oxides of Mo and Cr were decomposed in metallic states with increasing ion fluence. In the case of TiO 2 /Ag/TiO 2 , Ag colloids were formed in process of a dip-coating of the sol–gel method, and the Ag atoms were dispersed into deeper layer by a grain boundary diffusion. Ion beam mixing in the TiO 2 films produced a slight increase in the optical absorption of visible light.

Optical and structural changes of silica glass substrates implanted with Cu and O ions and subjected to thermal annealing, are examined as a function of the implantation sequence by optical absorption, Rutherford Backscattering Spectrometry (RBS) and thin film X-ray diffraction (XRD) measurements. Before annealing, the distribution of Cu is affected by the implantation sequence and O- followed by Cu-implantation leads to fewer Cu nanoparticles than the Cu- followed by O ion implantation. After annealing, however, the redistribution behavior of Cu and optical absorption features are similar for both co-implanted samples. Nanocrystals of Cu2O are mainly formed by annealing and the absorption peaks at about 340, 450 and 480 nm are observed for the co-implanted samples. The peaks are possibly evidence for the presence of the copper oxide nanocrystals.

Changes in the microstructure and mechanical properties of the surface of glassy carbon implanted with 1.15 MeV Ti ions were examined by Rutherford backscattering spectrometry, Raman spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy and ultra-microindentation measurements. It was found that the surface of glassy carbon was changed to an amorphous structure by Ti ion implantation. The thickness of the amorphous layer, as estimated by the transport of ions in matter (TRIM) simulation, was approximately 1 μm. The glassy carbon surface is composed of many granules which were also increased in size by ion implantation. However, this increase in size was sufficiently small compared with the indenter radius that it had only a minor influence at an early stage of the indentation measurements. The implanted Ti was in the carbide state of TiC. The hardness and elastic modulus were increased by approx. 2.5- and 3.5-fold due to the modification in structure by ion implantation.

In order to find the optimum conditions to obtain films with high photocatalytic property by sol-gel method, depth profiling of oxygen in TiO x film deposited on SiO 2 was carried out using resonant backscattering of 3.045 MeV He ions by the nuclear reaction of 16 O(α, α) 16 O. Depth profiling of hydrogen in the TiO x film was also conducted using elastic recoil detection analysis (ERDA). For the depth profiling by the resonant backscattering analysis, it is necessary to change the incident energy of He ions from about 3.03 to 3.1 MeV in steps of less than 10 keV. In our analyzing system, the ion beam energy of He ++ was scanned by changing a bias voltage supplied to the target holder up to +30 kV without changing the accelerator terminal voltage. The effect of the bias voltage supplied on the sample holder on the energy and the yield of the oxygen peak relative to the titanium and the silicon signal were investigated. The automatic analysis system and the analyzed results are presented.

Using double ion species implantation of metal and oxygen ions, we have examined the possibility of synthesis of metal-oxide fine particles in glass or sapphire surface. Characteristics of ion implanted silica glass and sapphire were examined by RBS, XRD and optical (absorption and photo-luminescence) measurements. 1.8 MeV 1×1017 Cu+/cm2 implantation into silica glass and a successive heat treatment of 1000°, 1h in the air can make Cu fine particles. 1.8 MeV 1×1017 Cu+/cm2 and 1.0 MeV 1×1017 O+/cm2 implantation into silica glass and the successive heat treatment can synthesis Cu2O fine particles of about 8 nm in radius. 1.8 MeV 5×1016 Ti+/cm2 and 1.0 MeV 1×1017 O+/cm2 into sapphire and the successive heat treatment can synthesis Ti02 fine particles of about 10 nm in radius. The TiO2 particles were rutile-type with (200) orientation, which may be related to the (0001) orientation of sapphire substrate. Luminescence from defects in sapphire substrate was observed, but luminescence from the particles could not be detected.

The thickness of the nitride layer formed by a high fluence nitrogen implantation to a metal surface is limited mainly because of the sputtering effects and the migration of the implanted nitrogen towards the surface. We have investigated nitrogen depth profiles implanted to several kinds of metals theoretically by Monte Carlo simulation using the dynamic-SASAMAL code and experimentally by RBS and NRA using the 15 N(p,????) 12 C reaction. In this paper, the saturation fluence and the saturated nitride thickness were calculated for 1???200 keV nitrogen implantations into several kinds of metals (Al, Ti, Fe, Zr, and Hf). In order to find the method to overcome the limited thickness and the severe radiation damage problem at the high fluence implantations necessary for the saturation, the nitrogen depth profiles for an energy scanning implantation with a uniform and a non-uniform energy distribution was calculated and compared with those of mono-energetic implantations.

高線量でZr表面に注入した窒素の挙動を調べるため,50keVの15Nを室温で注入量1×1017から1×1018ions cm-2で注入し,その深さ方向分布を共鳴核反応分析法により測定して,動的なモンテカルロシミュレーションにより得られた理論分布と比較した.核反応は,共鳴エネルギーが429 keVの15N(p,αγ)12Cを用い,ガンマ線を測定した.15Nの注入を14Nの注入と前後して行うことにより,注入した窒素がその注入段階によってどのように分布するかの詳細を明らかにすることができた.又,電算機シミュレーションにおいては窒素濃度に上限を設けない計算と,窒素濃度は50%で飽和し,それ以上の濃度の窒素は照射損傷濃度に依存して表面方向に拡散すると仮定した2種類の計算を行い,測定結果と比較した.その結果,注入した窒素は濃度50%で飽和し,それを超えた窒素は表面に向かって拡散することが分かった.又,注入の後の段階で注入した窒素は,初期の段階で注入したものより広がって分布すること,並びに初期の段階で注入した窒素は引き続く注入により,中央部が押し分けられ二つのピークに分かれることが明らかになった.

Nitride ceramics are formed on metal surfaces by high-fluence nitrogen implantation and the mechanical and chemical properties of the surfaces are modified. However, the thickness of the nitride layer is limited by the sputtering effect and the migration of implanted nitrogen towards the surface. In this work, we studied these effects for nitrogen implantation into several kinds of metals (Al, Si, Ti, V, Fe, Co, Ni, Zr, Nb, Mo, Ta and W) by Monte Carlo simulations using the dynamic sasamal code in comparison with the experimental results obtained by NRA. The dynamic sasamal code takes into account target alterations which occur under high-fluence implantations, so that dynamic changes in composition, deposited energy, retained probability of the implanted ion, sputtering effects, etc. with fluence can be calculated. For nitrogen implantations into metals, the saturated nitrogen concentration is assumed to equal that of the saturated nitride phase and nitrogen atoms above stoichiometry are assumed to diffuse towards the surface. The depth profiles of nitrogen concentration and the retention of nitrogen obtained by the code agree very well with the experimental results for 50 keV nitrogen implantations into metals with fluences of 10 17 –10 18 ions cm −2 . The calculated sputtering yields were compared with the semi-empirical values.

Polycrystalline SiC and a bilayer of thin Zr deposited on SiC (Zr-SiC) were implanted with 50 keV 15 N ions at fiuences in the range (0.25–1.5) × 10 18 ions cm −2 at elevated temperature up to 1100 °C. After implantation, the depth profiles of the elements were measured using Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA) and Auger electron spectroscopy (AES). The structure and chemical bonding state of the implanted layer were investigated by glancing angle X-ray diffraction (G-XRD) and X-ray photoelectron spectroscopy (XPS). It was found that the maximum concentration and halfwidth of the nitrogen profile implanted at 1100 °C were strongly decreased in comparison with those at room temperature, and nitrogen implantation into SiC at 1100 °C resulted in a composite layer of β -Si 3 N 4 and SiC. In Zr-SiC, the interfacial reaction of Zr and SiC was observed at high temperature, and a composite layer of ZrC, β -Si 3 N 4 and SiC was formed by nitrogen implantation.

A simple energy scanning and data acquisition system for nuclear resonance analyses with a narrow resonance is presented. Ion beam energy was scanned by directly supplying a bias in the range −30 to +30 kV to a target holder. Details of the energy scanning and the data acquisition are described. Some examples for the depth profiling of nitrogen implanted into metals using the system with the nuclear reaction 15N(p, αγ)12C at 429 keV are shown in comparison with the calculated results by a Monte Carlo simulation. The data analysis program used to obtain depth profiles from excitation curves is also shown. The target is divided into layers of uniform concentration and the reaction probability in a layer is calculated from a starting depth profile obtained from raw data, using the normalized error function with Gaussian approximation for the overall energy spread. This leads to a very simple computer program, fast to operate with a small computer.

Amorphous (a-)Ge films deposited on air-cleaved CaF 2 (111) substrates were irradiated with 1.8 MeV Si ions, and the microstructure of the irradiated Ge films was examined by using Rutherford backscattering spectrometry combined with channeling technique, X-ray diffraction measurement and transmission electron microscopy. It was found that the ion irradiation can induce solid phase epitaxial growth (SPEG) of Ge (111) films even at low sample temperature ( T s ) of approximately 200°C, although the films included some randomly oriented crystals. In contrast to this, a-Ge films practically did not crystallize during heat treatment at 200°C and the polycrystal films were only obtained when temperatures reached more than 500°C. These results suggest that ion irradiation enhances the SPEG of a-Ge/CaF 2 heterosystem at relatively low T s values.

Changes in the surface morphology and optical transmittance of polymers, poIy(methyl methacrylate) (PMMA) thin films on quartz glass plates and poly(tetrafluoroethylene) (PTFE) sheets, induced by megaelectronvolt ion implantation, were examined using different ion species, energies, ion current densities and doses. The polymer surface showed remarkable depression after ion implantation. On PMMA, the depression increased with dose and saturated after a dose of about 5×1014 ions cm−2. Higher energy and heavier ions made a larger depression generally. On PTFE, implantation of heavy ion species made a small depression and the dependence on dose was almost linear in the range 1014 to 1015 ions cm−2. PMMA changed its appearance from transparent to white, light brown, brown and finally bla'jk with dose, because of UV-visible light absorption. The width of the absorption band increased with dose, and the implantation of heavier ion species caused wider and larger absorption. Some annihilation of light absorption with time was found at room temperature. Roughening of the ion implanted surface was also observed.

鋭い共鳴幅の核反応を利用した共鳴核反応法は表層における軽元素の深さ分析に特に優れた分析法である.この方法では,分析に用いるプロトンやヘリウムなどのエネルギーを一定の照射量ごとに細かなエネルギーステップで変化させ,発生するガンマ線や粒子線を測定し,励起曲線を得る.本報告ではこの励起曲線を自動的に得るためのエネルギー走査型データ取り込みシステムについて述べた.プロトンエネルギーは加速電圧を一定に保ったまま,試料ホルダーに印加したバイアス電圧を-30kVから+30kVの範囲で一定のビーム電流ごとに~0.5kV刻みで変化させることで走査した.これにより,測定誤差の少ないなめらかな励起曲線を得ることができた.

Retention of nitrogen implanted into various kinds of metals (Al, V, Ti, Fe, Co, Ni, Zr, Nb, Mo, Ta, and W) was calculated by the dynamic-SASAMAL code assuming planer surface binding energy and diffusion toward the surface for nitrogen over the concentration of saturated nitride phase. As the value of surface binding energy ( E s ), the sum of the heat of sublimation of the metal ( H s ) and the heat of formation of the nitride ( H f ) times the nitrogen concentration ( C ) at the surface layer was used ( E s = H s + CH f ). The effects of values of H s , H f , and the displacement threshold energy on the retention were studied. The agreements between the calculated results and the experimental results obtained by NRA using 15 N(p, αγ) 12 C reaction were satisfactory for depth profiles and retention of nitrogen implanted into metals of Al, Ti, Ni, and Zr at a wide range of fluence from 6 × 10 16 to 6 × 10 17 ions cm −2 .

Dynamic SASAMAL code takes into account target alterations which occur under high fluence implantations, so that dynamic changes of the atomic composition, the retention probability of implanted ions, etc., with the fluence can be calculated. The model calculations have been applied for implantations of nitrogen ions of energy 50 keV into zirconium with fluences of 10 17 –10 18 ion cm -2 , assuming (1) no special diffusion and (2) upward diffusion for the extra atoms over stoichiometry. Also, the saturation concentration of nitrogen is assumed to be equal to the saturated nitride phase. Depth profiles of the atomic composition and the retention rate of implanted ions obtained by the calculations were compared with the results of nuclear reaction analysis, and the results obtained with the assumption of “upward diffusion” agreed very well with the experimental results. The depth profiles of the energy deposited by the implanted ions on the target atoms through electronic and nuclear interactions also were calculated. These are discussed in comparison with the results of glancing-angle X-ray diffraction.

Zirconium films were implanted with 15 N ions of energy 50 keV to a total fluence of 1 × 10 18 ions cm -2 in an attempt to study the formation process and thermal stability of ZrN layers produced by high fluence implantation of nitrogen. Subsequent to the implantation at room temperature, samples were annealed at temperatures of 300 °C–900 °C. The depth profiles of the implanted nitrogen were measured by nuclear reaction analysis using the 15 N(p,αγ) 12 C at E R = 429 keV, and the surfaces were examined by thin film X-ray diffraction (XRD) and scanning electron microscopy. There were many blisters 0.2–0.4 μm in diameter on the surface of the as-implanted samples and double peaks were observed in the nitrogen depth profiles; they were in both sides of the mean projected range. It was found that most of the blisters became extinct after annealing above 400 °C, and the XRD peak (111) intensity was increased with the increase in the annealing temperature. Moreover, 14 N and 15 N implantations were superimposed on Zr samples in order to study the atomic migration of nitrogen at each stage of high fluence implantation. It was found that the decrease in the peak at the deeper layers was related to blister extinction and nitrogen diffusion into underling zirconium which could be correlated with radiation damage induced by post-implanted ions.

Au films on optically flat Pyrex glasses or MgO single crystals were implanted with Si, Ni and Au ions with ion energies from 0.75 to 3 MeV and doses from of 5 × 1013 to 5 × 1016 ions cm-2. The changes of their surfaces were investigated from measurements of the surface profiles and light reflection and/or scattering, and from observations by scanning electron microscopy (SEM). After ion implantation the surface showed a depression. The depression increased with increasing dose and mass of implanted ions. The ion-implanted surface became smoother than that of the as-deposited one. The intensity of light scattering was decreased and a metallic brilliance was observed after the implantation. The depression and the morphology changes were caused by sputtering and grain growth. In the SEM observations, the implanted regions were contrasted with as-deposited regions as blacker in secondary electron images and as whiter in composition images of reflected electrons. The impurity level of the films appeared to diminish after the ion implantation.

Au films are deposited on air-cleaved MgO(100) substrate by forward sputtering under various conditions of ion energy and ion species and the differences in their structural features are examined. The films have a mixture of (111) and (100) orientations. When the ion energy decreases or when the ion mass increases, the growth of (100)-oriented deposits is enhanced. Mostly (100)-oriented Au films are obtained below 500 °C. The defect density in Au films deposited by Au 3+ ions seems to be lower than that in Au films deposited by other ions. The surface morphology is also changed by the ion species. With lighter ions (C + , O + ) a relatively uniform surface is observed, while with heavier ions (Si + , Au 3+ ) a grain structure becomes clear. From these results it is believed that the structural features of Au deposits can be favourably changed by forward-sputtering deposition.

Depth profiles of nitrogen implanted into Zr with an energy of 50 keV were calculated by dynamic SASAMAL code with three different assumptions for the diffusion of excess atoms over stoichiometry, i.e., ‘no diffusion', ‘both-sides-diffusion’ and ‘upward-diffusion'. To distinguish nitrogens implanted certain stage of implantations, alternate implantations of 15N and 14N were used. The results were compared with the experimental results by the resonance nuclear reaction analysis, NRA. For 15N implantation with fluences from 1 × 1017 to 1 × 1018 ions/cm2, the calculated results with ‘upward-diffusion’ agreed very well with the NRA results for all fluences. For the depth profile of pre-implanted 15N (1 × 1017 ions/cm2), which was changed by the subsequent 14N implantation with fluences of 1 ∼ 10 × 1017 ions/cm2, the agreement with the NRA results was satisfactory until the 14N fluence did not exceed 5 × 1017 ions/cm2, but for higher fluences, the retained probabilities of 15N obtained by the ‘upward-...

High-fluence implantations of 100 keV N2+ ion into a zirconium layer deposited by an electron beam were carried out at room temperature and at liquid-nitrogen temperature with and without nitrogen gas of a pressure of 1 × 10−4 Torr. Depth profiles of atom concentrations were determined by Rutherford backscattering spectrometry, Auger electron spectroscopy, and resonance nuclear reaction analysis. The experimental results were compared with the theoretical results obtained by Monte Carlo simulations of the dynamic-SASAMAL code. The depth profiles measured by RBS agreed well with the calculated profiles for all fluences from 1 × 1017 to 5 × 1017 ions/cm2, but differed from those obtained by AES indicating the existence of easily released nitrogen in the Zr specimen implanted with nitrogen at high fluence. Glancing angle X-ray diffraction was used to confirm zirconium nitride formation.

Surface swelling of sintered silicon-nitride, sintered alumina and single crystal sapphire implanted with 0.7-3 MeV N+. Si+ and Ni+ ions to 5×1013-5×1017 ions/cm2, were evaluated by measuring the step height of the implanted region with a surface profile meter. The swelling became measurable when the dose exceeded 1×1014-1×1015 ions/cm2, increased with increasing dose, then saturated. In the case of implantation of heavier ions or for low temperature implantation, the dose required to induce a measurable swelling is lower and the step height for saturation is higher. The step height profile versus dose for silicon-nitride is not similar to the one for alumina or sapphire. The swelling of the single crystal is larger than that of the sintered material, generally. After the annealing (1200°C, 1 hr in vacuum), the swelling is reduced about 30%. This phenomenon of surface swelling can be simulated semi-qualitatively by Monte Carlo calculation.

Diamond like carbon (DLC) films were prepared by a plasma source ion implantation on silicon wafer and 440 C stainless steel substrates. Methane (CH/sub 4/), acetylene (C/sub 2/H/sub 2/), toluene (C/sub 6/H/sub 5/CH/sub 3/,) and benzene (C/sub 6/H/sub 6/) were used as working gases for the plasma and the structure and properties of the films were compared. Radio frequency power was used to produce a glow discharge plasma. High negative voltage pulses of -20 kV were applied to a substrate holder to accelerate ions in the plasma. The surface morphology was observed by a field emission scanning microscope (SEM) and a atomic force microscope (AFM). Structure information of the DLC films was obtained by Raman spectroscopy. The composition analysis of the DLC films and film/substrate interface was carried out using Auger electron spectroscopy (AES). Hydrogen content of the films was estimated by a elastic recoil dispersion analysis (ERDA). Hardness of the films was measured by a indentation method. The friction coefficients of the films were measured with the aid of a reciprocating sliding tester. The results showed that the structure of the films and the interface structure and the properties varied with chemical structure of working gases. The DLC film prepared from CH/sub 4/ plasma was thinner than others. The films prepared from C/sub 2/H/sub 2/, C/sub 6/H/sub 5/CH/sub 3/ and C/sub 6/H/sub 6/ plasma were thicker and exhibited high hardness. The integrated intensity ratio of "D" peak and "G" peak, I/sub D/I/sub G/, of the Raman spectra, was changed depend on working gases. The DLC films prepared by PSII had good wear properties.

The optimum dose for forming SOI structures suitable for devices by nitrogen implantation and subsequent annealing has been widely investigated for mono-energetic implantation. When nitrogen concentration is under the stoichiometric value of Si/sub 3/N/sub 4/, numerous small silicon islands are contained in the Si/sub 3/N/sub 4/ layer formed by annealing and cause a leakage current across the layer. When the concentration is above stoichiometry, nitrogen bubbles are formed and the layer becomes porous and fragile. By energy scanning or plural energy implantation, it is possible to keep the nitrogen concentration on the stoichiometric value over the wide range of depth. The optimum fluences for each energy in triple energy implantations (25 keV+50 keV+75 keV and 25 keV+50 keV+100 keV) were estimated by computer simulation using dynamic SASAMAL code. The implantations with these energies and fluences were performed. The nitrogen depth profiles were measured by NRA and compared with the calculated profiles. Surface topography was observed by AFM. The measured depth profile by NRA showed wide plateau of stoichiometric concentration of Si/sub 3/N/sub 4/ and the surface was very smooth even after high fluence implantation of 1.45/spl times/10/sup 18/ ions/cm/sup 2/ with the triple energy implantations.

Surface swelling of MeV Si ion implanted single crystal silicon was studied, with changing ion energies, sample temperature as well as dose. The effect of annealing was also examined. Swelling can be observed about 3/spl times/10/sup 13/ ions/cm/sup 2/ for 100 K implantation, and higher doses are required for higher temperature implantation, especially over 300 K. Saturation of swelling is also observed and the maximum value is almost proportional to the range of implanted ions. On the annealing, there is little effect up to 850 K, but the swelling except accumulation of implanted ions almost completely disappeared after successive 1000 K 30-min annealing. We can conclude that the measurement of swelling is an easy and non-destructive tool to investigate the behavior of damages or defects induced by ion implantation.

Heteroepitaxial crystallization of a-Ge films deposited on CaF 2 (111) substrate induced by 1.8 MeV Si ion beam irradiation has been studied by using Rutherford backscattering spectrometry (RBS) combined with channeling technique as an in situ monitor for the crystallization process. Parameters for irradiation were direction ( -aligned and random: 5° off ), ion dose and ion current intensity (Ic). Samples were heated only by beam heating and sample temperature (Ts) was varied with Ic. It was found that pronounced epitaxial crystallization of Ge films occured at Ts ≥ about 200°C (where Ic ≥ 2 μA/cm 2 ). However, the defects still remained at any Ts (or Ic) in current experiment. The crystallization appeared to be saturated at high ion dose. In addition, the Ge films crystallized at high Ts (large Ic) were peeled in air probably due to internal stress induced by irradiation. The crystallization rate for aligned irradiation was slightly lower than that for random irradiation.

Amorphous (a-) Ge films were deposited on air-cleaved CaF2 (111) substrates at different deposition temperatures (Td). The films were irradiated with 0.9 MeV Ge or Si ions at low ion current intensity (1c) l00nA/cm2. Their structural changes were studied by Rutherford backscattering spectrometry (RBS) -channeling technique and thin film x-ray diffraction (XRD) measurement. It was found that the films were epitaxially crystallized by Ge and Si ion irradiation although they included randomly oriented grains. Ge ion irradiation was more effective for the crystallization than Si ion irradiation. However, the amount of the randomly oriented grains was slightly higher when using Ge ions. On the other hand, ion irradiation to the films prepared at high Td also exhibited higher incidence of randomly oriented grains.

Silica glasses were implanted with 1.8 MeV Cu ions at a dose of 0.32–1.3×1017 ions/cm2 at a temperature of less than 300° C. The thermal annealing of the samples was carried out in air in the range of 300–1100° C, and the effects on the formation and growth of Cu nanoparticles were examined as a function of ion dose and annealing temperature using Rutherford backscattering spectrometry and optical absorption measurements. It was found that the broad absorption band between 250–400 nm was increased and the average radius of Cu particles was slightly decreased where the total concentration of Cu was not changed up to 700° C. This suggests that small Cu precipitates were generated. The surface plasmon resonance absorption at approximately 570 nm was clearly developed at 800° C. In addition, the average radius of Cu particles increased as the annealing temperature increased from 800–1000° C. However, the concentration of Cu began to decrease at temperatures above 800° C. The plasmon absorption also decreased in intensity with increasing temperature, which indicated that the amount of Cu particles had decreased. The decrease of the amount of Cu particles was affected by ion dose.

By means of an in-situ Rutherford-backscattering-spectrometry (RBS) channeling technique, we have investigated creation and reduction of irradiation damage in single-crystalline TiN films induced by 1.8 MeV carbon beam. Both the effects of ion channeling and of beam heating on variation of damage level are shown briefly by successive irradiations on the order of 1017 C+/cm2 under different conditions. It is shown that the aligned irradiation with a high-intensity beam repairs almost completely the damage produced by random irradiation where the sample is heated to about 450^°C b y t h e b e a m, w h e r e a s s i m p l e h e a t t r e a t m e n t u p t o 600^°C r e s u l t s i n l e s s r e d u c t i o n o f t h e d a m a g e.

The effects of 100 keV N+2 and Ar+ ion implantation on atomic mixing and the hardness in 400 A Ti deposited SiC were investigated by means of Monte Carlo simulation, He backscattering, Auger electron spectroscopy, and Vickers indentation method. It was shown that the carbon concentration near the surface was increased remarkably by N+2 ion implantation at 1000°C, and those C atoms formed TiC. The experimental results far exceed the results obtained by the Monte Carlo simulation based on binary collision model. It was concluded that the C atoms, which originated from lattice sites in SiC by collision cascades, would migrate to the upper Ti layer by radiation enhanced thermal diffusion and react with Ti atoms.

窒化ケイ素などのように比較的軽いマトリックスでできたセラミック原料粉体中に含まれる,それより重い微量元素の定量に対する粒子励起X線(PIXE)分析法の適用性を調べた.試料としては,入射陽子の最大投影飛程に比べて十分に厚いものを用い,得られたスペクトルの解析は次のようにして行った.一般にセラミック原料粉体の粒径は~1μm程度あり,化学的処理なしに十分に薄い試料を調製するのは困難である.逆に,入射陽子の最大投影飛程に比べて十分に厚いペレット状の試料なら特別な試料調製なしに容易に成形することができる.このような厚い試料から得られるPIXEスペクトルの解析は複雑で,大型電子計算機による処理が一般的であるが,著者らは次のような比較的簡単な方法を考案した.まず大型計算機を用いて,対象とするマトリックス中に,単位量(1ppm)の微量元素が含まれている場合に,単位量(1μC)の陽子を照射して得られるX線強度Yを求めておく.パーソナルコンピューターを用いたオンライン処理においては,データからバックグラウンドX線を差し引いた残りのスペクトル中のピークを探し,このピークに対応する元素のYの値を用いてガウス分布の理論スペクトルを発生させ,これと,データのピーク強度との比較からその元素の含有率を決定する.この方法で窒化ケイ素を分析した結果は,誘導結合プラズマ発光分析法による結果とよく一致した.この方法はセラミック原料のうち,比較的軽い元素の化合物である窒化ケイ素,炭化ケイ素,酸化アルミニウム,酸化マグネシウムなどに含まれる不純物元素の定量分析に適用できる.

Implantation into silica glasses with O and Cu ions and subsequently thermal annealing in vacuum were carried out, and the optical and structural changes were examined as a function of O ion dose by optical absorption and thin film X-ray diffraction measurements. In the Cu implantation alone, Cu nanoparticles were formed in the silica glasses after annealing at 800-1000/spl deg/C. On the other hand, co-implantation of O and Cu ions suppressed the growth of Cu nanoparticles, and promoted the formation of Cu/sub 2/O nanoparticles. Further increase in the O ion dose led to the formation of CuO nanoparticles as well as Cu/sub 2/O nanoparticles.