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Ion microbeam technique
Abstracts mental observations of surface feature elaboration is discussed from net growth to net erosion conditions and models for their explanation are considered. It is concluded that whilst much data has been accumulated much of this has been in such diverse experimental conditions that precise modelling in atomic terms is difficult and generalizations are treacherous. A clear need for structured, extensive studies exist with very precise parameter definition and control.
Ion microbeam technique G Giitz and R Miihle, Friedrich-Schiller-Universitiit Physik Max- Wien-Platz 1, Jena 6900, DDR
Jena, Sektion
An overview of ion microbeam systems and their main elements will be given. The emission characteristics of Ga, AuSi and AuBe liquid metal ion sources are presented. In particular, results concerning the mass spectrum of an AuSi alloy ion source in dependence on the alloy composition and the total source current are reported. The ion-optical properties of an E x B type mass separator and the obtained mass resolution are demonstrated. Possible applications of ion microbeam systems are discussed. Finally, initial results obtained with a simple ion beam system with a Ga liquid metal ion source will be described.
the physical parameters that govern it. Ichimura’ has calculated with a Monte Carlo technique the background for many elements to obtain the backscattering correction factor, but it is only in the case of aluminium’ that calculation has been accurate enough to be compared with experiment. We have distinguished the three components of the background : primary electrons, secondary electrons and Auger electrons, all of them having suffered elastic or inelastic events on their way through the solid. Energy distribution of the primary backscattered electrons may be calculated by a simple transport model where elastic and inelastic scattering are separated. For copper it may be represented, in a wide range of energy, by a simple exponential law’. Escape of KLL aluminium Auger electrons has been simulated with the help of a layer by layer model: accuracy is very good on a more than 100 eV energy range4. But for a full spectrum simulation, the Monte Carlo technique is the best one. Results of simulation for aluminium and copper are compared with experimental spectra. Many other experimental curves, obtained with a good energy resolution analyzer, will also be presented References ’ S Ichimura and R Shimizu, Surf Sci, 112,386 (1981); 115,259 (1982) ; 124, L49 (1983). ‘R Shimizu and S Ichimura. Surf&i, 133,250 (1983). 3D Jousset and J P Langeron, J Vat Sci Technol, AZ, 989 (1987). 4D Jousset, P. Dubot, J P Langeron and M Villatte, Le Vide, les Couches Minces (1987).
Modern trends in secondary ion mass spectroscopy V T Cherepin, Institute of Metal Physics, 36 Vernadsky Str, 252680 Kiev 142, USSR
Acad Sci Ukr SSR
The major trends in the development of the physical analysis of the emission of secondary ions and in the application of new analytical apparatus are discussed. Physical experiments, performed in ultrahigh vacuum, study the mass, energy and takeoff angle distributions of the secondary ions and are combined with scattering analysis to obtain information which is compared with the results of computer calculations. The applied analytical work is aimed at increasing the sensitivity of the measurements at a submicron spatial resolution and high layer-by-layer and mass resolution. New developments are based on the use of liquid-metal ion sources and ion optical systems which combine the properties of the ion microscope and ion microprobe with systems for dynamic beam control.
Background in Auger electron spectroscopy J P Langeron, CECMICNRS, Vitry-sur-Seine, LIESSeIENS, F94230 Cachan, France
15, rue Georges Urbain, F94407 61, Avenue du Prtsident Wilson,
Until recently Auger electron spectroscopy (AES) users have mainly taken into account only the Auger peaks since the electron background disappears when using the derivative mode of recording spectra. But the direct mode n(E) shows the background and the difficulty to subtract it: we need more information on 1054
Electron-laser-ion structures
technology for treatment
of semiconductor
V M Koleshko and B S Evseev, Institute of Electronics, Byelorussian Acad Sci, Ya Kolas Str 6812, Minsk-90, 220841 USSR The fundamentals of the theory of the electron-laser-ion technological (ELIT) process of non-equilibrium gradient-zone crystallization in semiconductors are presented. The solid-to-liquid phase transition is achieved by means of energetic pulses similar to those that may be used in laser annealing’. The laser flux J, with energy hw > Eg creates a liquid phase on one side of the semiconductor. From the other side the semiconductor is irradiated by a laser flux Jo with energy ho < E, at which the crystal is transparent. The flux Jo is absorbed in the liquid phase at some depth. Moreover, if the energy absorbed from the flux J, exceeds the heat of solidification of the semiconductor and compensates the heat flow away from the melted region then the flux J,, may maintain this region in a metastable state with flux J, turned off. Applying a potential difference to the solid-liquidsolid system (e.g. by means of electron or ion probes) and introducing a dopant into the liquid phase by means of ion implantation, one may create conditions for the controlled motion of the doped liquid phase across the semiconductor. The liquid phase is electrically neutral everywhere except at the boundaries and has the structure of an electron melt. The boundaries of the liquid phase are in the regions of forward-biased and reversebiased potential barriers. Under the influence of the electric field of the reverse-biased barrier, electrons are injected into the solid phase. The Lorentz force caused by the field acts on the positive
Ion microbeam technique G Giitz and R Miihle, Friedrich-Schiller-Universitiit Physik Max- Wien-Platz 1, Jena 6900, DDR
Jena, Sektion
An overview of ion microbeam systems and their main elements will be given. The emission characteristics of Ga, AuSi and AuBe liquid metal ion sources are presented. In particular, results concerning the mass spectrum of an AuSi alloy ion source in dependence on the alloy composition and the total source current are reported. The ion-optical properties of an E x B type mass separator and the obtained mass resolution are demonstrated. Possible applications of ion microbeam systems are discussed. Finally, initial results obtained with a simple ion beam system with a Ga liquid metal ion source will be described.
the physical parameters that govern it. Ichimura’ has calculated with a Monte Carlo technique the background for many elements to obtain the backscattering correction factor, but it is only in the case of aluminium’ that calculation has been accurate enough to be compared with experiment. We have distinguished the three components of the background : primary electrons, secondary electrons and Auger electrons, all of them having suffered elastic or inelastic events on their way through the solid. Energy distribution of the primary backscattered electrons may be calculated by a simple transport model where elastic and inelastic scattering are separated. For copper it may be represented, in a wide range of energy, by a simple exponential law’. Escape of KLL aluminium Auger electrons has been simulated with the help of a layer by layer model: accuracy is very good on a more than 100 eV energy range4. But for a full spectrum simulation, the Monte Carlo technique is the best one. Results of simulation for aluminium and copper are compared with experimental spectra. Many other experimental curves, obtained with a good energy resolution analyzer, will also be presented References ’ S Ichimura and R Shimizu, Surf Sci, 112,386 (1981); 115,259 (1982) ; 124, L49 (1983). ‘R Shimizu and S Ichimura. Surf&i, 133,250 (1983). 3D Jousset and J P Langeron, J Vat Sci Technol, AZ, 989 (1987). 4D Jousset, P. Dubot, J P Langeron and M Villatte, Le Vide, les Couches Minces (1987).
Modern trends in secondary ion mass spectroscopy V T Cherepin, Institute of Metal Physics, 36 Vernadsky Str, 252680 Kiev 142, USSR
Acad Sci Ukr SSR
The major trends in the development of the physical analysis of the emission of secondary ions and in the application of new analytical apparatus are discussed. Physical experiments, performed in ultrahigh vacuum, study the mass, energy and takeoff angle distributions of the secondary ions and are combined with scattering analysis to obtain information which is compared with the results of computer calculations. The applied analytical work is aimed at increasing the sensitivity of the measurements at a submicron spatial resolution and high layer-by-layer and mass resolution. New developments are based on the use of liquid-metal ion sources and ion optical systems which combine the properties of the ion microscope and ion microprobe with systems for dynamic beam control.
Background in Auger electron spectroscopy J P Langeron, CECMICNRS, Vitry-sur-Seine, LIESSeIENS, F94230 Cachan, France
15, rue Georges Urbain, F94407 61, Avenue du Prtsident Wilson,
Until recently Auger electron spectroscopy (AES) users have mainly taken into account only the Auger peaks since the electron background disappears when using the derivative mode of recording spectra. But the direct mode n(E) shows the background and the difficulty to subtract it: we need more information on 1054
Electron-laser-ion structures
technology for treatment
of semiconductor
V M Koleshko and B S Evseev, Institute of Electronics, Byelorussian Acad Sci, Ya Kolas Str 6812, Minsk-90, 220841 USSR The fundamentals of the theory of the electron-laser-ion technological (ELIT) process of non-equilibrium gradient-zone crystallization in semiconductors are presented. The solid-to-liquid phase transition is achieved by means of energetic pulses similar to those that may be used in laser annealing’. The laser flux J, with energy hw > Eg creates a liquid phase on one side of the semiconductor. From the other side the semiconductor is irradiated by a laser flux Jo with energy ho < E, at which the crystal is transparent. The flux Jo is absorbed in the liquid phase at some depth. Moreover, if the energy absorbed from the flux J, exceeds the heat of solidification of the semiconductor and compensates the heat flow away from the melted region then the flux J,, may maintain this region in a metastable state with flux J, turned off. Applying a potential difference to the solid-liquidsolid system (e.g. by means of electron or ion probes) and introducing a dopant into the liquid phase by means of ion implantation, one may create conditions for the controlled motion of the doped liquid phase across the semiconductor. The liquid phase is electrically neutral everywhere except at the boundaries and has the structure of an electron melt. The boundaries of the liquid phase are in the regions of forward-biased and reversebiased potential barriers. Under the influence of the electric field of the reverse-biased barrier, electrons are injected into the solid phase. The Lorentz force caused by the field acts on the positive