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Microstructure of sputter-deposited 304L stainless steel
Classified abstracts 420-429 resulted in a decrease in the number of faults from 6 per cent to practically zero. F G Zakirov and V N llin, Elektron Tekh Elektron SVCh, 7, 1970, 85-89 (in Russian).
III. Vacuum applications 30. EVAPORATION AND SPUTTERING 30 420. Quartz crystal microbalance applicable to the chemical reactions of thin metal films. (Japan) A quartz crystal microbalance with stability better than 2 × 10-r/day has been constructed for measurements of weight changes due to chemical reaction. The 5 MHz and 3.58 MHz quartz crystals have sensitivities for mass determination of 5.64× 107 Hz/(g/cm 2) and 2.89 × 107 Hz/(g/cm~) respectively. Oscillation circuits and some new attachments and techniques for the present apparatus are described. Some examples of the weight gain data are presented for the reactions of gases with vacuum deposited metal films. Y Hasegawa et al, J Vac Soc Japan, 13 (9), 1970, 296-302 (in Japanese). 30 421. Direct-current electrical breakdown of thin titania films in high vacuum. (USA) Electrical breakdown of thin (60-100/~) titania films under high dc fields in high (10 -° torr) vacuum is discussed. Titania coatings were applied to A12Oa insulators, using the same process as in coating of A1203 microwave windows to reduce multipactoring. Recorded breakdown voltages and current dependence, along with the appearance of the coatings after testing, suggest the occurrence of a reduction of the titania films to a lower-order semiconducting oxide similar to what would happen in bulk titania. It is therefore evident that such coatings are not feasible on insulators subjected to high tangential dc fields. K G Bouchard, J Vac Sci Technol, 7 (5), Sept~Oct 1970, 531-533. 30 422. Analysis of a ring cavity thin-film deposition source. (USA) Equations are derived which allow the prediction of the thickness distribution of thin films deposited from sources possessing vertical sides and axial symmetry. These equations are in the form of three double integrals which must be integrated over a variable region of integration. Some correlation with experiment is also reported. L D Feisel, J Vac Sci Technol, 7 (5), Sept~Oct 1970, 517-527. 30 423. Preparation and superconducting properties of niobium-zirconium thin films. (USA) N b - Z r thin films (3000~,000 /~ thick) have been prepared by dc sputtering at 350°C and 630°C. Measurements of the J~-H characteristics in transverse fields of up to 85 kOe and of T~'g were carried out as a function of composition. The effects of different substrate materials and deposition rates on the superconducting properties of Nb-66 at per cent Zr thin films deposited at 630~C were also investigated. The results show a distinct dependence of J~-H data on the substrate temperature: Maximum critical fields of up to 60 kOe at 10 ~ A/cm 2 are observed for films deposited at 350°C, whereas some films deposited at 630°C are still superconducting'at 85 kOe with current densities of 105 A/cm ~. H J Spitzer, J Vac Sci Techno[, 7 (5), Sept~Oct 1970, 537-542. 30 424. Formation of amorphous films. (USA) The similarities and differences between the liquid and amorphous phases are discussed. It is concluded from experimental data that the atomic arrangement in "ordered agglomerates with spherical close packing" differs from that in small crystallites. A review of experimental results for alloys, for elements with homopolar binding, and for semimetals and metals indicates that the metastable disorder in these groups of materials displays different characteristics. Interpretations for the varying degree of thermal stability, for sizedependent transitions, and for the kinetics of the transformation are given. Based on these considerations, a concept for the formation and crystallization of amorphous films is developed which shows the progressive change of the characteristics among the groups of materials. K H Behrndt, J Vac Sci Technot, 7 (3), Ala)./June 1970, 385-398.
30 425. Nucleation and oriented growth of chemically formed sulphide and oxide films. (USA) The kinetics of the sulpfiidation and oxidation of evaporated zinc and cadmium films in sulphur and oxygen have been investigated. Between 100 Dand 250~C a rapid gas uptake occurs which may be described by k.log(t-t0). Subsequently, a slow reaction is observed, the time dependence being represented by a logarithmic expression or by a general power law of the type k.t TM. Electron-optical and x-ray studies reveal a substantial effect of nucleation and recrysta|lization processes on the kinetics of the layer growth. The following phases of layer growth could be confirmed: (1) coating of the metal with a very thin ( d ~ 50 A.) nonoriented layer; (2) growth of oriented sulphide or oxide nuclei with diameters of i0~-103 ,~; (3) coalescence of these nuclei and formation of a coherent layer; in the case of CdS and CdO, formation of medium-size epitaxial crystallites; (4) formation of whiskers at elevated temperatures. Measurements of zinc and cadmium single crystals gave similar results, but the reaction rate is much slower and the degree or orientation depends strongly on the pretreatment of the metal surfaces. The results show that nucleation and recrystallization processes affect considerably the kinetics of the formation of thin films on metals. From this it can be concluded that it is necessary to modify models of film growth, which in most cases are based on a homogenous layer structure. G Hecht et al, J Vac Sci Technol, 7 (5), Sept/Oct 1970, 547-551. 30 426. Structure of evaporated PtSi on Si. (USA) Due to the many conflicting reports on the structure of evaporated Pt on Si substrates, a study of the system was made with special emphasis on possible experimental errors. It is shown that for annealing temperatures up to 700'~C the only phases present are Pt and PtSi for evaporated and sputtered Pt. 30 427. Vacuum systems for sputtering. (USA) Oil diffusion pumped vacuum system operation has been examined in the light of sputtering system requirements. It was found that cleanliness is an important problem because of the low deposition rates of the sputtering process. A model for a cleaning action of the throughput of the sputtering gas was der!ved. The model indicated that certain changes in the operating procedure of the vacuum system would increase the cleaning action of the sputtering gas significantly. The requirement is that the throughput of the sputtering gas be maximum. Measurements of partial pressure of 02 vs Ar throughput show the model to be essentially correct. The action of the high throughput on oil backstreaming was also measured. It was found that high throughput reduces oil vapour backstreaming considerably. G A Shirn and W L Patterson, J Vac Sci Technol, 7 (3), May/June 1970, 453-458. 30 428. Preparation and epitaxy of sputtered films of ferroelectric Bi4Ti3Ozz. (USA) Single crystals of ferroelectric Bi~Ti,~O12 are known to possess novel optical properties with potential use in optical memory or display applications. There is interest in duplicating these properties in thin films. Suitability of reactive and rf sputtering for preparation of stoichiometric films has been investigated. Films from stoichiometric targets were Bi deficient. Using Bi-rich targets stoichiometric films were obtained by depositing at substrate temperatures (typically in the range of 500°-700~C) high enough to prevent inclusion of the more volatile bismuth oxide in excess of the Bi4Ti3Ol~ composition. Good quality epitaxial growth has been achieved on MgO and epitaxial Pt substrates. W J Takei et al, J Vac Sci Technol, 7 (3), May/June 1970, 442-448. 30 429. Microstructnre of sputter-deposited 304L stainless steel. (USA) Deposits of 304L stainless steel from 0.002-0.064 in-thick were produced at rates from 0.002-0.00075 in/h by triode sputtering techniques. Substrates were maintained at temperatures from 1°-800°C. The 304L alloy was found to be removed by krypton atoms at a rate of 4.6 g/A-h (2.2 atoms/ion) with the target at t 500 V. The 0.064-inthick sample produced on a substrate held at 1:C showed a variation in columnar grain microstructure through the deposit thickness. Chemical analysis showed that the alloy composition of the deposits was nearly the same as the target. The data indicated that the deposits had slightly more chromium, but less nitrogen and carbon than the target. Electron microprobe data indicated the deposits were uniform
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III. Vacuum applications 30. EVAPORATION AND SPUTTERING 30 420. Quartz crystal microbalance applicable to the chemical reactions of thin metal films. (Japan) A quartz crystal microbalance with stability better than 2 × 10-r/day has been constructed for measurements of weight changes due to chemical reaction. The 5 MHz and 3.58 MHz quartz crystals have sensitivities for mass determination of 5.64× 107 Hz/(g/cm 2) and 2.89 × 107 Hz/(g/cm~) respectively. Oscillation circuits and some new attachments and techniques for the present apparatus are described. Some examples of the weight gain data are presented for the reactions of gases with vacuum deposited metal films. Y Hasegawa et al, J Vac Soc Japan, 13 (9), 1970, 296-302 (in Japanese). 30 421. Direct-current electrical breakdown of thin titania films in high vacuum. (USA) Electrical breakdown of thin (60-100/~) titania films under high dc fields in high (10 -° torr) vacuum is discussed. Titania coatings were applied to A12Oa insulators, using the same process as in coating of A1203 microwave windows to reduce multipactoring. Recorded breakdown voltages and current dependence, along with the appearance of the coatings after testing, suggest the occurrence of a reduction of the titania films to a lower-order semiconducting oxide similar to what would happen in bulk titania. It is therefore evident that such coatings are not feasible on insulators subjected to high tangential dc fields. K G Bouchard, J Vac Sci Technol, 7 (5), Sept~Oct 1970, 531-533. 30 422. Analysis of a ring cavity thin-film deposition source. (USA) Equations are derived which allow the prediction of the thickness distribution of thin films deposited from sources possessing vertical sides and axial symmetry. These equations are in the form of three double integrals which must be integrated over a variable region of integration. Some correlation with experiment is also reported. L D Feisel, J Vac Sci Technol, 7 (5), Sept~Oct 1970, 517-527. 30 423. Preparation and superconducting properties of niobium-zirconium thin films. (USA) N b - Z r thin films (3000~,000 /~ thick) have been prepared by dc sputtering at 350°C and 630°C. Measurements of the J~-H characteristics in transverse fields of up to 85 kOe and of T~'g were carried out as a function of composition. The effects of different substrate materials and deposition rates on the superconducting properties of Nb-66 at per cent Zr thin films deposited at 630~C were also investigated. The results show a distinct dependence of J~-H data on the substrate temperature: Maximum critical fields of up to 60 kOe at 10 ~ A/cm 2 are observed for films deposited at 350°C, whereas some films deposited at 630°C are still superconducting'at 85 kOe with current densities of 105 A/cm ~. H J Spitzer, J Vac Sci Techno[, 7 (5), Sept~Oct 1970, 537-542. 30 424. Formation of amorphous films. (USA) The similarities and differences between the liquid and amorphous phases are discussed. It is concluded from experimental data that the atomic arrangement in "ordered agglomerates with spherical close packing" differs from that in small crystallites. A review of experimental results for alloys, for elements with homopolar binding, and for semimetals and metals indicates that the metastable disorder in these groups of materials displays different characteristics. Interpretations for the varying degree of thermal stability, for sizedependent transitions, and for the kinetics of the transformation are given. Based on these considerations, a concept for the formation and crystallization of amorphous films is developed which shows the progressive change of the characteristics among the groups of materials. K H Behrndt, J Vac Sci Technot, 7 (3), Ala)./June 1970, 385-398.
30 425. Nucleation and oriented growth of chemically formed sulphide and oxide films. (USA) The kinetics of the sulpfiidation and oxidation of evaporated zinc and cadmium films in sulphur and oxygen have been investigated. Between 100 Dand 250~C a rapid gas uptake occurs which may be described by k.log(t-t0). Subsequently, a slow reaction is observed, the time dependence being represented by a logarithmic expression or by a general power law of the type k.t TM. Electron-optical and x-ray studies reveal a substantial effect of nucleation and recrysta|lization processes on the kinetics of the layer growth. The following phases of layer growth could be confirmed: (1) coating of the metal with a very thin ( d ~ 50 A.) nonoriented layer; (2) growth of oriented sulphide or oxide nuclei with diameters of i0~-103 ,~; (3) coalescence of these nuclei and formation of a coherent layer; in the case of CdS and CdO, formation of medium-size epitaxial crystallites; (4) formation of whiskers at elevated temperatures. Measurements of zinc and cadmium single crystals gave similar results, but the reaction rate is much slower and the degree or orientation depends strongly on the pretreatment of the metal surfaces. The results show that nucleation and recrystallization processes affect considerably the kinetics of the formation of thin films on metals. From this it can be concluded that it is necessary to modify models of film growth, which in most cases are based on a homogenous layer structure. G Hecht et al, J Vac Sci Technol, 7 (5), Sept/Oct 1970, 547-551. 30 426. Structure of evaporated PtSi on Si. (USA) Due to the many conflicting reports on the structure of evaporated Pt on Si substrates, a study of the system was made with special emphasis on possible experimental errors. It is shown that for annealing temperatures up to 700'~C the only phases present are Pt and PtSi for evaporated and sputtered Pt. 30 427. Vacuum systems for sputtering. (USA) Oil diffusion pumped vacuum system operation has been examined in the light of sputtering system requirements. It was found that cleanliness is an important problem because of the low deposition rates of the sputtering process. A model for a cleaning action of the throughput of the sputtering gas was der!ved. The model indicated that certain changes in the operating procedure of the vacuum system would increase the cleaning action of the sputtering gas significantly. The requirement is that the throughput of the sputtering gas be maximum. Measurements of partial pressure of 02 vs Ar throughput show the model to be essentially correct. The action of the high throughput on oil backstreaming was also measured. It was found that high throughput reduces oil vapour backstreaming considerably. G A Shirn and W L Patterson, J Vac Sci Technol, 7 (3), May/June 1970, 453-458. 30 428. Preparation and epitaxy of sputtered films of ferroelectric Bi4Ti3Ozz. (USA) Single crystals of ferroelectric Bi~Ti,~O12 are known to possess novel optical properties with potential use in optical memory or display applications. There is interest in duplicating these properties in thin films. Suitability of reactive and rf sputtering for preparation of stoichiometric films has been investigated. Films from stoichiometric targets were Bi deficient. Using Bi-rich targets stoichiometric films were obtained by depositing at substrate temperatures (typically in the range of 500°-700~C) high enough to prevent inclusion of the more volatile bismuth oxide in excess of the Bi4Ti3Ol~ composition. Good quality epitaxial growth has been achieved on MgO and epitaxial Pt substrates. W J Takei et al, J Vac Sci Technol, 7 (3), May/June 1970, 442-448. 30 429. Microstructnre of sputter-deposited 304L stainless steel. (USA) Deposits of 304L stainless steel from 0.002-0.064 in-thick were produced at rates from 0.002-0.00075 in/h by triode sputtering techniques. Substrates were maintained at temperatures from 1°-800°C. The 304L alloy was found to be removed by krypton atoms at a rate of 4.6 g/A-h (2.2 atoms/ion) with the target at t 500 V. The 0.064-inthick sample produced on a substrate held at 1:C showed a variation in columnar grain microstructure through the deposit thickness. Chemical analysis showed that the alloy composition of the deposits was nearly the same as the target. The data indicated that the deposits had slightly more chromium, but less nitrogen and carbon than the target. Electron microprobe data indicated the deposits were uniform
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