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Evaporated single element metal film resistors
188
A B S T R A C T S ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
The m a s s spectrographic analysis o f a residual a t m o s p h e r e a b o v e silicon-705 in a 6-inch pump. E. D. TOLMIE, Vacuum, 15, No. 10, p. 497. The arrangement of a 6 in. pump group equipped with an omegatron is described and the results are given for analysis of residual gases above the pump charged with silicon-705. Spectra are given for various conditions of the system relating to ct~evron baffle temperature, temperature of baking and backing pressure. An interpretation of these results is made regarding the nature and sources of a number of gases and vapours in the system and some indication is given of suitable techniques in obtaining "clean" conditions in the UHV range employin~ such fluids as silicon-705. Role o f surface states in contributing to p-type carrier c o n c e n t r a t i o n o f v a c u u m deposited thin g e r m a n i u m films. R. R. HUMPHRIS and A. CATLIN, Solid-St. Electron. 8 (1965), pp. 957-960. Germanium films were deposited by evaporation on to heated single crystal calcium fluoride substrates, which were cleaved either in air or inside the vacuum system. Results indicate that structural defects and impurities probably are not responsible for the high concentration of acceptors (~l(PS/cm :~) typically found in deposited germanium films. It is therefore believed that surface states and the assodated space charge layer completely dominate the electrical characteristics of thin ( ~ 3000 A) deposited germanium films. I o n - b e a m deposition o f m e t a l films. A. R. WOLTER,Proc. IEEE Symposium on ":Vlolecular Concepts in Microelectronics", St. Louis, May 24, 25, 26 (1965), p. 2A-1. This paper describes experimental studies of ion-beam deposition of thin metal films. The potential of the method for maskless deposition of microelectronic circuits is considered, design of a deposition device is presented, and some properties of silver, copper and chromium films are examined. Specifically, the limitations placed on the quantity of metal deposited per unit time by space-charge repulsion and sputtering are examined. A description of an arc-discharge ion source and an electrostatic acceleration and focusing system is given. The structure of ion-beam-deposited silver, copper and chromium is shown to be very similar to vacuumevaporated films. The adhesion of silver, copper and chromium films to glass substrates was found to be exceptional for ion energies greater than 100 eV. The temperature coefficient of resistance of chromium films was less positive than that of vacuum-evaporated chromium films. This deposition technique has significant potential for microelectronic applications. R a r e earth o x i d e dielectrics. F. W. SCHENKEL,Vroc. IEEE Symposium on "Molecular Concepts in .~/Iicroelectronics", St. Louis, May 24, 25, 26 (1965), p. 2D-1. The working limitations imposed by the more commonly used dielectric materials in thin film capacitors, has spurred an investigation of the rare earth oxides. It is desirous to employ materials which exhibit a high dielectric constant, higher temperature operational capabilities, and a high breakdown potential all along with good stability. These combined qualities are difficult to obtain in any one given material. Some compromises must be made. However, some of the rare earth oxides have shown definite promise in pushing the state of the art forward. Thin film compounds of neodymium and dysprosium have yielded components capable of stable operation at temperatures of 500°C. The characteristics of both neodymium and dysprosium compounds as a function of their evaporation parameters are presented. The method of vacuum deposition for each material is described. Both electron bombardment and resistance heat evaporant sources have been utilized in these studies. The exact structure of these fihns is still somewhat questionable. Speculations have been made which relate certain chemical occurrences but further work remains to be done to tie down some of the unanswered questions. The results obtained warrant a close look at this group of materials for use in thin fihn circuit fabrication. D e s i g n charts for transient r e s p o n s e o f thin-film networks. W. W. HAPP, Electron. Technol. December'(1965), p. 36. A method of determining the correct thin-film circuit termination for a specified rise time and output waveform is demonstrated with an example. E v a p o r a t e d single e l e m e n t m e t a l film resistors. D. D. ZIMMERMAN,Proc. IEEE Symposium on "Molecular Concepts in Microelectronics", St. Louis, May 24, 25, 26 (1965), p. 2C-1. Thin metal film resistors were vacuum evaporated on to glass substrates. Experimental process parameters were varied
A B S T R A C T S ON M I C R O E L E C T R O N I C S
AND R E L I A B I L I T Y
189
to change the properties of the resistor films. Investigation of these properties has yielded data which are useful in selecting optimum process parameters for producing thin film resistors with the desired characteristics for use in microelectronic circuit designs. Vacuum systems capable of operating in the low 10 _6 torr range are used. Two evaporation techniques are employed; resistance heating and electron bombardment. Post-evaporation heat treatment is used to improve the resistor characteristics. The range of values of resistance most frequently encountered in electronic circuits can be produced using only the single elements, aluminium, chromium, tungsten and rhenium. Optical density determinations are used to evaluate sheet resistance gradients over the substrate area, thus providing a rapid method of optimising evaporation geometry and source design.
Temperature coefficient of v a c u u m deposited thin film resistors patterned with abrasive-jet and electron-beam milling. HELMUT SCHWARZ and E. T. CASTERLiNE. Proc. IEEE Symposium on "Molecular Concepts in Microelectronics", St. Louis, May 24, 25, 26 (1965), p. 2B-1. It has been shown experimentally and theoretically that the T C R (Temperature Coefficient of Resistance) of thin film resistors which are so thin that they are not continuous but consist of an array of islands separated from each other, depends at higher electrical fields slightly on the applied voltage and the number of lines that are scribed into the film to form a pattern to increase the resistance value of the film. As long as the T C R was positive the electron beam scribed resistors which had more and finer lines were smaller than those scribed with the sand-blast technique where fewer and wider lines were produced.
Residual-gas analysis of a DC-705 o i b d i t f u s i o n - p u m p e d u h v system. CHARLESM. GOSSELINand PAUL J. BRYANT, J. Vacuum Sci. TechnoL 2, No. 6, Nov.-Dec. (1965). The residual gases present in a DC-705 oil-diffusion-pump uhv system have been determined as a function of various trapping conditions. The system was equipped with a metal 2 in. oil-diffusion pump in series with a specially designed trap in which zeolite was used. The configuration of the trap permitted the trapping zone to be immersed in cryogenic liquids, e.g. L N 2. The effectiveness of the trap was determined as a function of temperature. A comparison of the residual gases is made for six conditions, including three trapping temperatures, while operating with zeolite and without zeolite.
Dielectric Properties of thin insulating films of photoresist material. JOE T. PIERCE and J. PAUL PRITCHARD,JR., Proc. IEEE Symposium on "Molecular Concepts in Microelectronics", St. Louis, May 24, 25, 26 (1965), p. 3B-1. This paper discusses measurements of the dielectric properties of thin insulating films of AZ-17* and KPR$. The properties include conductivity and dielectric constant as a function of frequency, voltage and temperature. Also, films have been temperature cycled from 3 ° to 500°K to determine if structural defects appear. These measurements show that specially prepared films are suitable as large area insulators for fabricating multilayer film circuits. To illustrate the advantages of using photoresist films for both insulator and etchresist, a brief description of a process for fabricating cryotrons will be presented. * Trademark of AZoplate Corporation. I Trademark of Eastman Kodak Company.
Thermal release of gas trapped in sites with a continuum of activation energies. K. ERENTS, W. A. GRANT and G. CARTER,Vacuum, 15, No. 11, p. 529. Expressions are derived analytically for the total rate of gas desorption from sites distributed in activation energy for desorption, when exposed to a time varying temperature schedule. Both uniform and slowly variable with energy population distributions are considered and the results compared with numerically computed data. For simple population distribution functions it is found that the desorption rate-temperature function is equally simple, and methods of deducing population distributions from desorption rate data are considered.
A B S T R A C T S ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
The m a s s spectrographic analysis o f a residual a t m o s p h e r e a b o v e silicon-705 in a 6-inch pump. E. D. TOLMIE, Vacuum, 15, No. 10, p. 497. The arrangement of a 6 in. pump group equipped with an omegatron is described and the results are given for analysis of residual gases above the pump charged with silicon-705. Spectra are given for various conditions of the system relating to ct~evron baffle temperature, temperature of baking and backing pressure. An interpretation of these results is made regarding the nature and sources of a number of gases and vapours in the system and some indication is given of suitable techniques in obtaining "clean" conditions in the UHV range employin~ such fluids as silicon-705. Role o f surface states in contributing to p-type carrier c o n c e n t r a t i o n o f v a c u u m deposited thin g e r m a n i u m films. R. R. HUMPHRIS and A. CATLIN, Solid-St. Electron. 8 (1965), pp. 957-960. Germanium films were deposited by evaporation on to heated single crystal calcium fluoride substrates, which were cleaved either in air or inside the vacuum system. Results indicate that structural defects and impurities probably are not responsible for the high concentration of acceptors (~l(PS/cm :~) typically found in deposited germanium films. It is therefore believed that surface states and the assodated space charge layer completely dominate the electrical characteristics of thin ( ~ 3000 A) deposited germanium films. I o n - b e a m deposition o f m e t a l films. A. R. WOLTER,Proc. IEEE Symposium on ":Vlolecular Concepts in Microelectronics", St. Louis, May 24, 25, 26 (1965), p. 2A-1. This paper describes experimental studies of ion-beam deposition of thin metal films. The potential of the method for maskless deposition of microelectronic circuits is considered, design of a deposition device is presented, and some properties of silver, copper and chromium films are examined. Specifically, the limitations placed on the quantity of metal deposited per unit time by space-charge repulsion and sputtering are examined. A description of an arc-discharge ion source and an electrostatic acceleration and focusing system is given. The structure of ion-beam-deposited silver, copper and chromium is shown to be very similar to vacuumevaporated films. The adhesion of silver, copper and chromium films to glass substrates was found to be exceptional for ion energies greater than 100 eV. The temperature coefficient of resistance of chromium films was less positive than that of vacuum-evaporated chromium films. This deposition technique has significant potential for microelectronic applications. R a r e earth o x i d e dielectrics. F. W. SCHENKEL,Vroc. IEEE Symposium on "Molecular Concepts in .~/Iicroelectronics", St. Louis, May 24, 25, 26 (1965), p. 2D-1. The working limitations imposed by the more commonly used dielectric materials in thin film capacitors, has spurred an investigation of the rare earth oxides. It is desirous to employ materials which exhibit a high dielectric constant, higher temperature operational capabilities, and a high breakdown potential all along with good stability. These combined qualities are difficult to obtain in any one given material. Some compromises must be made. However, some of the rare earth oxides have shown definite promise in pushing the state of the art forward. Thin film compounds of neodymium and dysprosium have yielded components capable of stable operation at temperatures of 500°C. The characteristics of both neodymium and dysprosium compounds as a function of their evaporation parameters are presented. The method of vacuum deposition for each material is described. Both electron bombardment and resistance heat evaporant sources have been utilized in these studies. The exact structure of these fihns is still somewhat questionable. Speculations have been made which relate certain chemical occurrences but further work remains to be done to tie down some of the unanswered questions. The results obtained warrant a close look at this group of materials for use in thin fihn circuit fabrication. D e s i g n charts for transient r e s p o n s e o f thin-film networks. W. W. HAPP, Electron. Technol. December'(1965), p. 36. A method of determining the correct thin-film circuit termination for a specified rise time and output waveform is demonstrated with an example. E v a p o r a t e d single e l e m e n t m e t a l film resistors. D. D. ZIMMERMAN,Proc. IEEE Symposium on "Molecular Concepts in Microelectronics", St. Louis, May 24, 25, 26 (1965), p. 2C-1. Thin metal film resistors were vacuum evaporated on to glass substrates. Experimental process parameters were varied
A B S T R A C T S ON M I C R O E L E C T R O N I C S
AND R E L I A B I L I T Y
189
to change the properties of the resistor films. Investigation of these properties has yielded data which are useful in selecting optimum process parameters for producing thin film resistors with the desired characteristics for use in microelectronic circuit designs. Vacuum systems capable of operating in the low 10 _6 torr range are used. Two evaporation techniques are employed; resistance heating and electron bombardment. Post-evaporation heat treatment is used to improve the resistor characteristics. The range of values of resistance most frequently encountered in electronic circuits can be produced using only the single elements, aluminium, chromium, tungsten and rhenium. Optical density determinations are used to evaluate sheet resistance gradients over the substrate area, thus providing a rapid method of optimising evaporation geometry and source design.
Temperature coefficient of v a c u u m deposited thin film resistors patterned with abrasive-jet and electron-beam milling. HELMUT SCHWARZ and E. T. CASTERLiNE. Proc. IEEE Symposium on "Molecular Concepts in Microelectronics", St. Louis, May 24, 25, 26 (1965), p. 2B-1. It has been shown experimentally and theoretically that the T C R (Temperature Coefficient of Resistance) of thin film resistors which are so thin that they are not continuous but consist of an array of islands separated from each other, depends at higher electrical fields slightly on the applied voltage and the number of lines that are scribed into the film to form a pattern to increase the resistance value of the film. As long as the T C R was positive the electron beam scribed resistors which had more and finer lines were smaller than those scribed with the sand-blast technique where fewer and wider lines were produced.
Residual-gas analysis of a DC-705 o i b d i t f u s i o n - p u m p e d u h v system. CHARLESM. GOSSELINand PAUL J. BRYANT, J. Vacuum Sci. TechnoL 2, No. 6, Nov.-Dec. (1965). The residual gases present in a DC-705 oil-diffusion-pump uhv system have been determined as a function of various trapping conditions. The system was equipped with a metal 2 in. oil-diffusion pump in series with a specially designed trap in which zeolite was used. The configuration of the trap permitted the trapping zone to be immersed in cryogenic liquids, e.g. L N 2. The effectiveness of the trap was determined as a function of temperature. A comparison of the residual gases is made for six conditions, including three trapping temperatures, while operating with zeolite and without zeolite.
Dielectric Properties of thin insulating films of photoresist material. JOE T. PIERCE and J. PAUL PRITCHARD,JR., Proc. IEEE Symposium on "Molecular Concepts in Microelectronics", St. Louis, May 24, 25, 26 (1965), p. 3B-1. This paper discusses measurements of the dielectric properties of thin insulating films of AZ-17* and KPR$. The properties include conductivity and dielectric constant as a function of frequency, voltage and temperature. Also, films have been temperature cycled from 3 ° to 500°K to determine if structural defects appear. These measurements show that specially prepared films are suitable as large area insulators for fabricating multilayer film circuits. To illustrate the advantages of using photoresist films for both insulator and etchresist, a brief description of a process for fabricating cryotrons will be presented. * Trademark of AZoplate Corporation. I Trademark of Eastman Kodak Company.
Thermal release of gas trapped in sites with a continuum of activation energies. K. ERENTS, W. A. GRANT and G. CARTER,Vacuum, 15, No. 11, p. 529. Expressions are derived analytically for the total rate of gas desorption from sites distributed in activation energy for desorption, when exposed to a time varying temperature schedule. Both uniform and slowly variable with energy population distributions are considered and the results compared with numerically computed data. For simple population distribution functions it is found that the desorption rate-temperature function is equally simple, and methods of deducing population distributions from desorption rate data are considered.