Photoelectron Spectra Of Amorphous Sixhy Alloy Films: The Effect Of Microstructure On The Si-2p Level Shift

Depending on the deposition conditions, amorphous SixH y alloy films prepared by planar rf reactive magnetron sputtering exhibit one of three types of microstructure: (i) type A with no discernible microstructural features down to the 20-Å level and with a smooth uniform density; (ii) type B consisting of high-density regions of 50-200-Å lateral dimensions separated by a low-density network; and (iii) a two-level (type C) microstructure consisting of 300-500-Å dimensions columns separated by a pronounced low-density network. The columns, in turn, are composed of 50-200-Å dimension high-density regions interspersed with low-density network. The Si-2p level in these alloy films, determined by x-ray photoelectron spectroscopy, is observed to be strongly influenced by the microstructure of the film. A shift in the Si-2p level, systematically varying with the hydrogen concentration, is observed in alloy films with type B and type C microstructures. No shift is observed, irrespective of the hydrogen concentration, in alloy films with type A microstructure. The photoelectron spectra are examined in the light of the vibrational spectra of the films as measured by Fourier transform infrared techniques. The dependence of the Si-2p level shift on the microstructure and the variation with hydrogen concentration are explained qualitatively in terms of the differences in the silicon-hydrogen bonding in amorphous SixHy films with dissimilar microstructures.6072530253

X-ray Photoemission Spectroscopy Of Pt-cu: A Canonical Alloy

The possibility of employing x-ray photoemission valence-band spectra in a quantitative fashion for elucidation of valence-electron structure changes induced by alloying is examined. The special, or "canonical," property of Pt1-xCux, that one of the components, Pt, displays no measurable core-level shift, permits extraction of such changes from core-level and valence-band data alone. A relation between the d-resonant level shifts and the centroid of the valence-band spectra is derived and comparison of the centroid and core-level shifts leads to the desired information. The analysis indicates that there is no charge transfer in the system and that only Cu has significant valence occupation changes upon alloying, corresponding to dehybridization. Furthermore, information regarding Fermi-energy shifts is extracted and not required as input the results suggest that the shifts of the Fermi levels cannot be identified with those of the work functions as in other work. Model calculations indicate that dehybridization is to be expected as an "antihybridization" effect for a narrow d-band metal in a wide d-band one. © 1981 The American Physical Society.2373177318

Surface Segregation In A Rh0.95cu0.05 Alloy

The surface composition of a Rh0.95Cu0.05 alloy equilibrated at different temperatures in the range 833 to 918 K has been determined by Auger Electron Spectroscopy. Preferential segregation of copper to the surface has been observed at all temperatures studied in accordance with current theoretical models. The heat of segregation of copper is evaluated to be 4 ± 2kcal/mole. © 1982.104567570van der Plank, Sachtler, (1968) J. Catalysis, 12, p. 35Cunha, Lam, Frety, (1981) Proc. 1st Brazilian Congr. on Catalysis, p. 100. , Rio de Janeiro, Instituto Brasileiro de PetroleoSundaram, da Cunha, Rogers, Kleiman, Laks, Effects of alloying and chemisorption on Auger line shapes in Cu-Pd (1982) Journal of Vacuum Science and Technology, 20Neave, Foxtur, Joyce, (1972) Surface Sci., 29, p. 411Webber, Rojas, Dobson, Chadwick, (1981) Surface Sci., 105, p. 20Wynblatt, Ku, (1977) Interfacial Segregation, , W.C. Johnson, J.M. Blakely, Am. Soc. for Metals, Metals Park, Ohi

On Directly Measuring Relative Fermi Energies Of Noble Metals And Their Alloys

We present the first evidence of direct measurement of relative Fermi energies in alloys and between pure metals. From applying the "atomic" concept of core hole final state screening, the Auger energy shift of noble metal A equals EF A-EF(x). High resolution Auger shifts in P1-x tCux,AuxCu1-x and AuxAg1-x demonstrate experimental verification of this simple relation. We find EF CuEF Au ≅ - 0.2 eV, and EF Pt ≅ EF Cu and EF Ag ≅ EF Au. © 1981.391111711174Ehrenreich, Schwartz, (1976) Solid State Physics, 31, p. 150Sellmyer, (1978) Solid State Physics, 33, p. 83Lang, Kohn, (1971) Phys. Rev., 3 B, p. 1215Lang, (1973) Solid State Physics, 28, p. 225Eastman, (1970) Phys. Rev., 2 B, p. 1Rivière, (1969) Solid State Surface Science, 1. , M. Green, Dekker, New YorkGelatt, Ehrenreich, (1974) Phys. Rev., 10 B, p. 398Watson, Hudis, Perlman, (1971) Phys. Rev., 4 B, p. 4139Lang, Williams, (1977) Phys. Rev., 16 B, p. 2408Williams, Lang, (1978) Phys. Rev. Lett., 40, p. 954Lang, Williams, (1979) Phys. Rev., 20 B, p. 1369Martensson, Johansson, Valence-Band and Core-Level Satellites in Nickel and Related Elements (1980) Physical Review Letters, 45, p. 482Johansson, Martensson, (1980) Phys. Rev., 21 B, p. 4427Martensson, Nyholm, Johansson, (1980) Phys. Rev. Lett., 45, p. 745Kleiman, Sundaram, Rogers, Summary Abstract: Auger shifts and characterization of electronic structure of alloys containing noble metals (1981) Journal of Vacuum Science and Technology, 18, p. XXXXKowalczyk, Pollak, McFeely, Ley, Shirley, (1973) Phys. Rev., 8 B, p. 2387Powell, Mandl, (1972) Phys. Rev. Lett., 29, p. 1153Yin, Tsang, Adler, Yellin, (1972) J. Appl. Phys., 43, p. 3464Weightman, Roberts, Johnson, (1975) J. Phys., 8 C, p. 550Roberts, Weightman, Johnson, (1975) J. Phys., 8 C, p. 1301Antonides, Janse, Sawatsky, (1977) Phys. Rev., 15 B, p. 1669Heine, (1967) Phys. Rev., 153, p. 673Hubbard, (1967) J. Proc. Phys. Soc., 92, p. 921V.S. Sundaram, J.D. Rogers and R. Landers (J. Vac. Sci. Tech., in press)Powell, (1973) Phys. Rev. Lett., 30, p. 1179Kleiman, Sundaram, Barreto, Rogers, (1979) Sol. St. Commun., 32, p. 919Kleiman, Sundaram, Rogers, de Moraes, (1981) Phys. Rev., 23 B, p. 3177Sundaram, Rogers, de Moraes, Kleiman, X-ray photoemission lineshapes and energies in PdxCu1-x (1981) Journal of Physics F: Metal Physics, 11, p. XXXXKleiman, (1981) Proceedings of the Second International Conference of Solid Films and Surfaces, , College Park, Maryland(1980) First Latin American Symposium on Surface Physics, , Niteroi, Brasi

Co Chemisorption On Pd; Effect Of Segregated Phosphorus

Auger Spectroscopy and Thermal Desorption Spectroscopy were used to determine the effect of P on the activation energy for desorption of CO from a Pd foil. The CO chemisorption energy on a clean Pd surface was coverage dependent, with a low coverage value of 32 kcal mole, in agreement with results for monocrystal low index faces. On a P segregated surface, however, a coverage independent CO chemisorption energy of 26 kcal mole was observed. From the shape of the P(L23VV) Auger line, it is concluded that segregated P is not in its elemental form. © 1982.1192-3L383L387Gibbs, (1961) The Scientific Papers of J.W. Gibbs, 1. , Dover, New YorkWynblatt, Ku, (1977) Interfacial Segregation, , W.C. Johnson, J.M. Blakely, ASM, Metals Park, OHKiskinova, Goodman, (1981) Surface Sci., 108, p. 64da Cunha, (1981) MS Thesis, , Institute of Physics, University of CampinasGerlach, Ionization Spectroscopy of Contaminated Metal Surfaces (1972) Journal of Vacuum Science and Technology, 8, p. 599Behm, Christmann, Ertl, Van Hove, (1980) J. Chem. Phys., 73, p. 2984Davies, Lambert, (1981) Surface Sci., 111, p. L671Ladas, Poppa, Boudart, (1981) Surface Sci., 102, p. 151Tracy, Palmberg, (1969) J. Chem. Phys., 51, p. 4852Redhead, (1962) Vacuum, 12, p. 203Mervyn, Baird, Wynblatt, (1979) Surface Sci., 82, p. 79Conrad, Ertl, Koch, Latta, (1974) Surface Sci., 43, p. 462Melles, Davis, Levenson, (1974) Phys. Rev., 9 B, p. 461

Systematics Of Final State Screening In 5d Metals

The experimental systematics of the Auger parameter, ε, in the 3d metal series have been well described in terms of a quasi-atomic model of screening. Whether these results are transferrable from a narrow to a wide d-band series has been moot. We present, for the first time, measurements of ε in the 5d series, manifesting systematics similar to those in the 3d series. Model calculations support the validity of the qam. © 1982.434257260George Kleiman, Appl. Surf. Sci. (in press) and references thereinHedin, (1965) Ark. Fys., 30, p. 231Gadzuk, (1976) Phys. Rev., 14 B, p. 2267Ley, Kowalczyk, McFeely, Pollack, Shirley, (1973) Phys. Rev., 8 B, p. 2392Kowalczyk, Pollack, McFeely, Ley, Shirley, (1973) Phys. Rev., 8 B, p. 2387Kowalczyk, Ley, McFeely, Pollack, Shirley, (1974) Phys. Rev., 9 B, p. 381Shirley, Martin, Kowalczyk, McFeely, Ley, (1977) Phys. Rev., 15 B, p. 544Lang, Williams, (1977) Phys. Rev., 16 B, p. 2408Lang, Williams, (1979) Phys. Rev., 20 B, p. 1369Williams, Lang, (1978) Phys. Rev. Lett., 40, p. 954Martensson, Johansson, Valence-Band and Core-Level Satellites in Nickel and Related Elements (1980) Physical Review Letters, 45, p. 482Martensson, Nyholm, Johansson, Chemical-Shift Effects and Origin of the Pd 3d Core-Level Satellite in CuPd Alloys (1980) Physical Review Letters, 45, p. 754Johansson, Martensson, (1980) Phys. Rev., 21 B, p. 4427Kleiman, Sundaram, Rogers, Summary Abstract: Auger shifts and characterization of electronic structure of alloys containing noble metals (1981) Journal of Vacuum Science and Technology, 18, p. 583On directly measuring relative Fermi energies of noble metals and their alloys (1981) Solid State Communications, 39, p. 1171To reduce systematic errors, we use X-ray transition energies from G.G. Johnson and E.W. White, X-ray Emission Wavelengths and KeV Tables for Non diffractive Analysis (ASTM Data Series DS 46, 1970) to determine Bi - Bj in Eq. (1). For the 5d-series, Bk and Kjjk were measured as described in the text. For the 3d-series, the corresponding energies were taken fromWagner, Riggs, Davis, Moulder, Mutenberg, (1979) The Handbook of X-ray Photoelectron Spectroscopy, , Perkin-Elmer Corpn, MinnesotaParry-Jones, Weightman, Andrews, On the comparison of the soft X-ray, X-ray photoemission and Auger electron spectra of the valence bands of Mg, Mg2Cu and Mg3Au (1975) Journal of Physics F: Metal Physics, 5 F, p. 590. , The 4d systematics appear to resemble those in Fig. 1Heine, (1967) Phys. Rev., 153, p. 673Hubbard, (1967) Proc. Phys. Soc., 92, p. 921J.D. Rogers, V.S. Sundaram, G.G. Kleiman, S.G.C. Castro, R.A. Douglas and A.C. Peterlevitz, J. Phys. F., in pressCastle, Hazell, West, (1979) J. Electron Spectrosc., 16, p. 97Castle, West, (1979) J. Electron Spectrosc., 16, p. 195Wagner, Taylor, Generation of XPS Auger lines by bremsstrahlung (1980) Journal of Electron Spectroscopy and Related Phenomena, 30, p. 83Sundaram, Rogers, Landers, (1981) J. Vac. Sci. Tech., 19, p. 117. , This reference describes the experimental details of the BAES techniqueEven if N7, rather than N6, levels were actually involved, for example, the correction would involve the spin orbit splitting, which varies smoothly throughout the 5d seriesAntonides, Janse, Sawatzky, (1977) Phys. Rev., 15 B, p. 1669The Hg spectra were measured in a Hg-Au amalgam. The energies of the Hg and Au photopeaks, as well as that of the Au M5N6 7N6 7 structure, correspond to accepted pure metal values for these quantities, suggesting correspondence of the amalgam and pure Hg Auger measurementsHohenberg, Kohn, (1964) Phys. Rev., 136, p. B864Kohn, Sham, (1965) Phys. Rev., 140, p. A1133Larkins, Semiempirical Auger-electron energies for elements 10 ≤ Z ≤ 100 (1977) Atomic Data and Nuclear Data Tables, 20, p. 313Gelatt, Jr., Ehrenreich, (1974) Phys. Rev., 10 B, p. 398There do not seem to be sufficient literature values of the quantities in Eq. (1) for 3d and 4d series transitions to determine the slopes in ε reliably, as we have done with the 5d serie

Interlayer Oxidation Via Pores In Multilayer Metallic Films: Ag/pd/ti/(111) Si

Corrosion of the titanium layer in a multimetallization silicon solar cell contact was characterized using scanning electron microscopy, electron microprobe analysis and Auger electron spectroscopy. The corrosion product is titanium oxide. The oxidizing agent(s) obtain(s) access to the inner titanium layer through pores in the outer silver layer. Solar cells that had been subjected to accelerated aging tests (high temperature and high humidity) as well as untested cells were examined. More net oxygen was found in the tested cells. The titanium oxide is inhomogeneous because it is localized at pores and distributed exponentially in depth (into the titanium layer). © 1981.7814965Buck, III, Leidheisher, Jr., (1958) Nature (London), 181, p. 1681Stern, Wissenberg, The Influence of Noble Metal Alloy Additions on the Electrochemical and Corrosion Behavior of Titanium (1959) Journal of The Electrochemical Society, 106, p. 759Fischer, Gareth, (1968) Proc. 7th Photovoltaic Specialists' Conf., p. 214. , November, 1968, IEEE, New YorkEnglish, Turner, (1972) J. Electron. Mater., 1, p. 1Speight, Cooper, (1975) Thin Solid Films, 25, p. 531Sharp, (1979) J. Vac. Sci. Technol., 16, p. 204Becker, Pollack, (1970) Proc. 8th Photovoltaic Specialists' Conf., p. 40. , 1970, IEEE, New YorkSpeight, Bill, (1973) Thin Solid Films, 15, p. 32