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3112. Interdiffusion in composition-modulated copper-gold thin films
Classified abstracts 3108-311 7 of Ti to a few percent. Pre-evaporation of a 300 ,~ thick CaF.~ parting layer allowed membrane removal by water-assisted peeling. Pressure testing showed membranes to have bulk tensile strength of 4.66.2,'< l09 dyn/cm 2 (68-92 kpsi) and to behave elastically. They could be mounted under high tension by heating while clamped to a high thermal expansion coefficient Nylon flange. V Y Pickhardt and D L Smith, J Vac Sci Tcchnol, 14 (3), 1977, 823825. 30 3108. Thin-film deposition using low-energy ion beams (2) Pb +
ion-beam deposition and analysis of deposits. Thin films of Pb were grown on C and NaCI substrates by retarding a 4-keV, mass-analyzed Pb + ion beam to a low energy before deposition. The films were examined using Rutherford backscattering analysis, scanning electron microscopy, and transmission electron microscopy. Adhesion was found to be independent of deposition energy for all deposits grown between 24 and 200 eV. The thickness, degree of surface coverage, and crystalline orientation are dependent on incident Pb + ion energy. 50 eV is an optimum energy of deposition when parameters such as space-charge expansion, self-sputtering, film thickness, and surface coverage are considered. As the deposition energy is increased above 50 eV, the crystalline structures of deposits grown on single-crystal NaCl substrates becomes more ordered with a strongly preferred (I00) orientation. High purity and homogeneity ef the deposits were attributed to the use of a mass-analyzed beam and the maintenance of ultra-high-vacuum conditions in the substrate chamber. (Canada) J Amano and R P W Lawson, J Vac Sci Technol, 14 (3), 1977, 831-835. 30
3109. Thin-film deposition using low-energy ion beams (3) Mg ÷ ion-beam deposition and analysis of deposits. (USA) The energy dependence of the growth characteristics of Mg thin films on C substrates deposited by retarding a 4-keV mass-analyzed ion beam of Mg + ions to a range of energies between 24 and 500 eV has been studied by Rutherford backscattering analysis and scanning electron microscopy. An incident Mg + beam energy of about 100eV produced the optimum film in the shortest time when space-charge spreading of the beam at low energies is compared with self-sputtering of the deposit at the higher energies. The adhesion of the films is energy dependent and improves at higher energies. This is thought to be due to a deeper penetration of the Mg + ions into the C substrates above 100 eV. (Canada) J Amano and R P W Lawson, J Vac Sci Technol, 14 (3), 1977, 836-839. 30 3110. Vacuum-evaporated films of chromium with the A-15 structure. (USA) Continuous thin films of Cr 200-400 A thick and predominantly consisting of the A-15 phase were grown by evaporation in high vacuum onto KCI and NaCI substrates held at 300°C. The films have a chemical purity of better than 98 ~ , determined by "~He Rutherford scattering. The A-I 5 phase is not stabilized by impurities. The lattice parameter determined by electron diffraction is 4.60 A. The grain size is about 500 A. The films did not show superconductivity down to 0.5 K. C J Doherty et al, J Appl Phys, 48 (5), 1977, 2050-2054. 30 3111, Perpendicular magnetic aniso~'opy in evaporated amorphous GdCo films. (USA) Amorphous GdCo films with strong perpendicular magnetic anisotropy were vacuum deposited by thermal evaporation of the constituents in an oxygen atmosphere of at least 3 × 10 -a torr. In this paper the fabrication technique and the magnetic properties of the resulting GdCo films will be reported. (Germany) A Brunseh and J Schneider, J Appl Phys, 48 (6), 1977, 2641-2643. 30
3112. Interdiffusion in composition-modulated copper-gold thin films.
(USA) Vapor-deposited Cu-Au thin films were produced containing composition modulations with wavelengths between 8 and 26 A. The modulations produced satellite peaks in the X-ray diffraction patterns. Amplification factors and the corresponding diffusion coefficients were obtained by measuring the decay rate of the satellite
664
intensities. The amplification facto) reached a maximunl at 17 A, and decreased at both shorter and longer wavelengths. Interdiffusion coefficients bctwecn 10--'~ and 10- ' ~ cm-'/sec were measured over the temperature range 200-260 C. The effective diffusion coefficient is linearly dependent on the function B2(A) for ,~-:. l0/~. From the wavelength dependence of the measured diffusivities, a gradientenergy coefficient of 4.7 • 10 -6 erg/cm was obtained and is in good agreement with theoretical estimates. These experimental results were compared with the predictions from a proposed model for diffusion on cubic lattices. W M Paulson and J E Hillard, J Appl Phys, 48 (6), 1977, 2117-2123. 30 3113. Apparatus for measuring the thermoelectric power of thin film and bulk samples. (USA) An apparatus for measuring the thermoelectric power (TEP) of bulk and thin film materials is described. Spring tension-welded thermocouple probes are used to make electrical contact with the sample surface. The apparatus is small, simple, and can be used under different environmental conditions at various temperatures. It is also designed so that the sample can be easily and quickly mounted and removed. Measurements taken on n-type and p-type bulk Bi2Te3 samples and a thin copper film are reported. The effects of sample thickness and surface conditions on the measured TEP values and criteria for minimizing errors are discussed. Y R Shen et al, Re) Sci lnstrum, 48 (6), 1977, 688-692. 30 3114. Self-supporting thin films--parting agent. (USA) To produce self-supporting thin films a substrate must be coated with a parting agent before the sample material is vacuum deposited on the substrate. We described a spin-coating method which is simpler, faster, and more reliable than our previous methods of applying the parting agent. E T Arakawa et al, Re) Sci hrstrum, 48 (6), 1977, 707-708. 30 3115. The microstructure of amorphous rare-earth/transition-metal thin films. (GB) An anisotropic microstructure has been discovered in vapourdeposited, amorphous rare-earth/transition-metal films. The structure consists of columnar regions of from 50-200 A, in diameter that are surrounded by a network of less dense material. The authors were able to produce a perpendicular component of magnetic anisotropy in amorphous G d - C o films by evaporation in an oxygen atmosphere of ~ 1 0 -6 torr. (Netherlands) H J Leamy and A G Dirks, J Phys D: Appl Phys, 10(8), 1977, L95-L98.
31. S P U T T E R I N G 31 3116. Study of calcia-stabilized zirconia thin-film sensors. (USA) The ionic transference number of if-sputtered calcia-stabilized zirconia (CSZ) thin films has been investigated, using the Nernst method, in the 300°-400°C temperature range and between l0 -'~ and 2~< 10 - t atm of oxygen partial pressure. E.M.F. measurements at 342°C on N i - N i O / C S Z / P t - O 2 galvanic cells show a voltage roughly 5% lower than the theoretical value and an ionic transference number of about 0.85. Possibilities of such cells being used as oxygen sensors were estimated. Rise times typically observed between 10 -3 and 10 -2 atm of oxygen were approximately 4 rain at 280°C and 5 s at 420°C. The influence of Pt deposition parameters on the response speed is pointed out. (France) M Croset et al, J Vac Sci Technol, 14 (3), 1977, 777-781. 31 3117. Some investigations on deposition and etching profiles in masked rf sputtering. (USA) Profiles of sputter-deposited films using a mask were measured and compared to theoretical profiles. A discontinuity in the slope of the film profile is shown to be due to the finite thickness of the mask. Backscattering in rf sputter etching is shown to cause two effects : an apparent enhanced etching rate near the mask edge and nonvertical edges of the etched groove. Significant improvement in the etching profile was obtained by using slow-etching electrodes and low gas pressures. B L Sopori and W S C Chang, J Vac Sci Technol, 14 (3), 1977,782-785.
ion-beam deposition and analysis of deposits. Thin films of Pb were grown on C and NaCI substrates by retarding a 4-keV, mass-analyzed Pb + ion beam to a low energy before deposition. The films were examined using Rutherford backscattering analysis, scanning electron microscopy, and transmission electron microscopy. Adhesion was found to be independent of deposition energy for all deposits grown between 24 and 200 eV. The thickness, degree of surface coverage, and crystalline orientation are dependent on incident Pb + ion energy. 50 eV is an optimum energy of deposition when parameters such as space-charge expansion, self-sputtering, film thickness, and surface coverage are considered. As the deposition energy is increased above 50 eV, the crystalline structures of deposits grown on single-crystal NaCl substrates becomes more ordered with a strongly preferred (I00) orientation. High purity and homogeneity ef the deposits were attributed to the use of a mass-analyzed beam and the maintenance of ultra-high-vacuum conditions in the substrate chamber. (Canada) J Amano and R P W Lawson, J Vac Sci Technol, 14 (3), 1977, 831-835. 30
3109. Thin-film deposition using low-energy ion beams (3) Mg ÷ ion-beam deposition and analysis of deposits. (USA) The energy dependence of the growth characteristics of Mg thin films on C substrates deposited by retarding a 4-keV mass-analyzed ion beam of Mg + ions to a range of energies between 24 and 500 eV has been studied by Rutherford backscattering analysis and scanning electron microscopy. An incident Mg + beam energy of about 100eV produced the optimum film in the shortest time when space-charge spreading of the beam at low energies is compared with self-sputtering of the deposit at the higher energies. The adhesion of the films is energy dependent and improves at higher energies. This is thought to be due to a deeper penetration of the Mg + ions into the C substrates above 100 eV. (Canada) J Amano and R P W Lawson, J Vac Sci Technol, 14 (3), 1977, 836-839. 30 3110. Vacuum-evaporated films of chromium with the A-15 structure. (USA) Continuous thin films of Cr 200-400 A thick and predominantly consisting of the A-15 phase were grown by evaporation in high vacuum onto KCI and NaCI substrates held at 300°C. The films have a chemical purity of better than 98 ~ , determined by "~He Rutherford scattering. The A-I 5 phase is not stabilized by impurities. The lattice parameter determined by electron diffraction is 4.60 A. The grain size is about 500 A. The films did not show superconductivity down to 0.5 K. C J Doherty et al, J Appl Phys, 48 (5), 1977, 2050-2054. 30 3111, Perpendicular magnetic aniso~'opy in evaporated amorphous GdCo films. (USA) Amorphous GdCo films with strong perpendicular magnetic anisotropy were vacuum deposited by thermal evaporation of the constituents in an oxygen atmosphere of at least 3 × 10 -a torr. In this paper the fabrication technique and the magnetic properties of the resulting GdCo films will be reported. (Germany) A Brunseh and J Schneider, J Appl Phys, 48 (6), 1977, 2641-2643. 30
3112. Interdiffusion in composition-modulated copper-gold thin films.
(USA) Vapor-deposited Cu-Au thin films were produced containing composition modulations with wavelengths between 8 and 26 A. The modulations produced satellite peaks in the X-ray diffraction patterns. Amplification factors and the corresponding diffusion coefficients were obtained by measuring the decay rate of the satellite
664
intensities. The amplification facto) reached a maximunl at 17 A, and decreased at both shorter and longer wavelengths. Interdiffusion coefficients bctwecn 10--'~ and 10- ' ~ cm-'/sec were measured over the temperature range 200-260 C. The effective diffusion coefficient is linearly dependent on the function B2(A) for ,~-:. l0/~. From the wavelength dependence of the measured diffusivities, a gradientenergy coefficient of 4.7 • 10 -6 erg/cm was obtained and is in good agreement with theoretical estimates. These experimental results were compared with the predictions from a proposed model for diffusion on cubic lattices. W M Paulson and J E Hillard, J Appl Phys, 48 (6), 1977, 2117-2123. 30 3113. Apparatus for measuring the thermoelectric power of thin film and bulk samples. (USA) An apparatus for measuring the thermoelectric power (TEP) of bulk and thin film materials is described. Spring tension-welded thermocouple probes are used to make electrical contact with the sample surface. The apparatus is small, simple, and can be used under different environmental conditions at various temperatures. It is also designed so that the sample can be easily and quickly mounted and removed. Measurements taken on n-type and p-type bulk Bi2Te3 samples and a thin copper film are reported. The effects of sample thickness and surface conditions on the measured TEP values and criteria for minimizing errors are discussed. Y R Shen et al, Re) Sci lnstrum, 48 (6), 1977, 688-692. 30 3114. Self-supporting thin films--parting agent. (USA) To produce self-supporting thin films a substrate must be coated with a parting agent before the sample material is vacuum deposited on the substrate. We described a spin-coating method which is simpler, faster, and more reliable than our previous methods of applying the parting agent. E T Arakawa et al, Re) Sci hrstrum, 48 (6), 1977, 707-708. 30 3115. The microstructure of amorphous rare-earth/transition-metal thin films. (GB) An anisotropic microstructure has been discovered in vapourdeposited, amorphous rare-earth/transition-metal films. The structure consists of columnar regions of from 50-200 A, in diameter that are surrounded by a network of less dense material. The authors were able to produce a perpendicular component of magnetic anisotropy in amorphous G d - C o films by evaporation in an oxygen atmosphere of ~ 1 0 -6 torr. (Netherlands) H J Leamy and A G Dirks, J Phys D: Appl Phys, 10(8), 1977, L95-L98.
31. S P U T T E R I N G 31 3116. Study of calcia-stabilized zirconia thin-film sensors. (USA) The ionic transference number of if-sputtered calcia-stabilized zirconia (CSZ) thin films has been investigated, using the Nernst method, in the 300°-400°C temperature range and between l0 -'~ and 2~< 10 - t atm of oxygen partial pressure. E.M.F. measurements at 342°C on N i - N i O / C S Z / P t - O 2 galvanic cells show a voltage roughly 5% lower than the theoretical value and an ionic transference number of about 0.85. Possibilities of such cells being used as oxygen sensors were estimated. Rise times typically observed between 10 -3 and 10 -2 atm of oxygen were approximately 4 rain at 280°C and 5 s at 420°C. The influence of Pt deposition parameters on the response speed is pointed out. (France) M Croset et al, J Vac Sci Technol, 14 (3), 1977, 777-781. 31 3117. Some investigations on deposition and etching profiles in masked rf sputtering. (USA) Profiles of sputter-deposited films using a mask were measured and compared to theoretical profiles. A discontinuity in the slope of the film profile is shown to be due to the finite thickness of the mask. Backscattering in rf sputter etching is shown to cause two effects : an apparent enhanced etching rate near the mask edge and nonvertical edges of the etched groove. Significant improvement in the etching profile was obtained by using slow-etching electrodes and low gas pressures. B L Sopori and W S C Chang, J Vac Sci Technol, 14 (3), 1977,782-785.