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A broad-band thin-film lumped-element circulator for 1·7 GHz band
World Abstracts on Microelectronics and Reliability resistor networks with temperature coefficients in the range of _+50 ppm/°C. The as-sputtered temperature coefficient of resistance (TCR) of tantalum nitride films with nitrogen content set for optimum stability is approximately - 1 3 0 ppm. Although near zero TCR's can be obtained by reducing the nitrogen content during sputtering, such films exhibit substantial negative changes when dc loaded. Networks were fabricated on aluminum oxide substrates using in-line sputtered tantalum nitrode films and vacuum evaporated chrome-gold conductive termination films. Anneal schedules (to remove structural defects) in the range of 460-510°C for 4 hr were found suitable for producing films with near zero TCR over a sheet resistance range of 30-75 D/square. Conventional photolithography techniques were used to delineate resistor networks with up to 20 resistors per network. After a thermal stabilization of 16 hr at 250°C, the resistors were anodized to ratio tolerances as close as 0.05 %. Resistances of 50 ~ to 20 kff~were manufactured on a single network. Load life and thermal aging results indicate no degradation in performance as a result of shifting the TCR by vacuum annealing. Temperature cycle changes were less than 0.01%. Resistor TCR tracking was less than 7 ppm/°C on 0-700 × 0.700 network. Resistor noise was measured and found not to differ from unannealed resistor films.
On sputtered thin-films of chrome, nitrided chrome and nickel-chromium. J. L. ABITA. Microelectron. & Reliab. 12, 111 (1973). Sputter deposited thin-film chromium, chromium nitride and nickel chromium have been evaluated for use in resistor fabrication. Some of the data obtained is qualitatively similar to that obtained in thin-film investigation, however, from a practical point of view the data contained herein is of a quantitative nature and might prove useful to those involved in thin-film resistor manufacture (results were obtained on a commercially available system). Relatively little data has been reported on reactively sputtered chromium in argon/nitrogen mixtures. The data presented here indicate that although not suitable for resistor fabrication, reactively sputtered chrome may be useful as thin-film thermistors. A bUevel thin film hybrid circuit containing crossovers, resistors, capacitors, and integrated circuits. T. E. BRADY and D. K. HINDERMANN. I E E E Trans. Parts, Hybrids & Packaoin9, PHP-9, No. 3 (Sept. 1973). p. 181. Here is a discussion on the fabrication, characterization, and economic considerations of a set of complex hybrid integrated circuits being used in exploratory switching applications. Several approaches to fabrication are discussed. One approach is unique in that it includes four distinct technologies in addition to simple thin film interconnections. They are (1) beam crossovers, (2) thin film resistors, (3) thin film capacitors, and (4) metalfized via holes to a backplane.
Resin attachment of semiconductor dice on to film circuits. P. C. G. NOLAN. Mieroeleetron. & Reliab. 12, 235 (1973). The article describes the results of 2 yr's work evaluating suitable conductive and insulating resins for the attachment of semiconductor dice. The resin attachment is considered and its advantages over the normal eutectic methods discussed. Detailed results of tests are shown for the materials finally selected. Non-polarized memory-switching characteristics of ZnTe thin films. T. OTA and K. TAKAHASHI. Solid St. Electron.
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16, 1089 (1973). ZnTe thin films were prepared by the conventional vacuum-deposition method. Polycrystalline thin films could be deposited on a glass substrate at substrate temperatures between 20 and 450°C. Epitaxial thin films could be obtained on GaAs and InAs single crystals at substrate temperatures higher than 200°C. Memory switching could be observed in metal ZnTe-metal sandwich devices prepared on glass substrates. Both switching transitions, from of f t o on and on to off, could be performed without changing the bias polarity if a suitable value of series resistance was selected for each transition. Typical values of the series resistor were 20 Kf~ for off" to on and 200 Q for on to off transitions. Transition from o0" to on is explained as a result of the formation of a filamentary path in the off state, followed by the formation of a metallic filament in the on state. Transition from on to offis considered a result of thermal rupture of the metallic filament. A broad-band thin-film lumped-element circulator for 1.7 GHz band. H. KATOH and T. ITANO. Papers of Tech. Group on Microwave. MW72-89, Inst. Electronics Comm. Engrs. Japan (Oct. 1972). A compact broad-band thin-film lumpedelement circulator for 1.7 GHz-band was fabricated by forming junction inductors on one side of the ferrite substrate and series resonant network for wideband on another side. The ferrite substrate of the circulator is as small as 14 x 14 ram. The circulator has a 20 dB isolation bandwidth of greater than 500 MHz centering at 1-7 GHz and an insertion loss of less than 1.3 dB. Before fabrication the basic relation of different junction pattern to the eigenvalue for in-phase and rotating excitation was measured and it was found that there was a part of inductance which did not participate in the nonreciprocal coupling and some distributed capacitance. The result was included in the design of the circulator and it was confirmed that rotating and in-phase eigenvalue of the circulator could be adjusted independently of one another by parallel capacitors and series resonant network for wideband, respectively. Ferrite substrate used is Ca V ferrite with a saturation magnetization of 250 ~ 500 G. Interdigital capacitors and strip inductors are made of evaporated Cr-Au and plated Au films by mean of microwave IC technique including wire bonding for crossover. A simplified approach to hybrid thermal design. R. Y. SCAPPLE and F. Z. KEISTER. Solid St. Technol. (Oct. 1973). p. 51. With the ever increasing requirements for higher power hybrids, thermal design considerations and a means for thermal analysis have become mandatory. A simplified method for analyzing the thermal resistance between a power dissipating element in a hybrid package and the package case is described. Methods for minimizing thermal resistance and for partitioning power elements are also discussed. Finally, some examples are given comparing calculated thermal resistances with actual resistances for various hybrid packaging designs. The results obtained using this simplified analysis are normally somewhat conservative. but for all practical purposes adequate for most hybrid applications.
Integrated M O S distributed RC networks for frequency selective circuits. S. M. BozIc. C. A. MILt,ER and R. I. SALAWU. Microelectron. & Reliab. 12, 139 (1973). A method of fabricating distributed RC networks for producing frequency selective circuits in IC form is proposed. An
On sputtered thin-films of chrome, nitrided chrome and nickel-chromium. J. L. ABITA. Microelectron. & Reliab. 12, 111 (1973). Sputter deposited thin-film chromium, chromium nitride and nickel chromium have been evaluated for use in resistor fabrication. Some of the data obtained is qualitatively similar to that obtained in thin-film investigation, however, from a practical point of view the data contained herein is of a quantitative nature and might prove useful to those involved in thin-film resistor manufacture (results were obtained on a commercially available system). Relatively little data has been reported on reactively sputtered chromium in argon/nitrogen mixtures. The data presented here indicate that although not suitable for resistor fabrication, reactively sputtered chrome may be useful as thin-film thermistors. A bUevel thin film hybrid circuit containing crossovers, resistors, capacitors, and integrated circuits. T. E. BRADY and D. K. HINDERMANN. I E E E Trans. Parts, Hybrids & Packaoin9, PHP-9, No. 3 (Sept. 1973). p. 181. Here is a discussion on the fabrication, characterization, and economic considerations of a set of complex hybrid integrated circuits being used in exploratory switching applications. Several approaches to fabrication are discussed. One approach is unique in that it includes four distinct technologies in addition to simple thin film interconnections. They are (1) beam crossovers, (2) thin film resistors, (3) thin film capacitors, and (4) metalfized via holes to a backplane.
Resin attachment of semiconductor dice on to film circuits. P. C. G. NOLAN. Mieroeleetron. & Reliab. 12, 235 (1973). The article describes the results of 2 yr's work evaluating suitable conductive and insulating resins for the attachment of semiconductor dice. The resin attachment is considered and its advantages over the normal eutectic methods discussed. Detailed results of tests are shown for the materials finally selected. Non-polarized memory-switching characteristics of ZnTe thin films. T. OTA and K. TAKAHASHI. Solid St. Electron.
19
16, 1089 (1973). ZnTe thin films were prepared by the conventional vacuum-deposition method. Polycrystalline thin films could be deposited on a glass substrate at substrate temperatures between 20 and 450°C. Epitaxial thin films could be obtained on GaAs and InAs single crystals at substrate temperatures higher than 200°C. Memory switching could be observed in metal ZnTe-metal sandwich devices prepared on glass substrates. Both switching transitions, from of f t o on and on to off, could be performed without changing the bias polarity if a suitable value of series resistance was selected for each transition. Typical values of the series resistor were 20 Kf~ for off" to on and 200 Q for on to off transitions. Transition from o0" to on is explained as a result of the formation of a filamentary path in the off state, followed by the formation of a metallic filament in the on state. Transition from on to offis considered a result of thermal rupture of the metallic filament. A broad-band thin-film lumped-element circulator for 1.7 GHz band. H. KATOH and T. ITANO. Papers of Tech. Group on Microwave. MW72-89, Inst. Electronics Comm. Engrs. Japan (Oct. 1972). A compact broad-band thin-film lumpedelement circulator for 1.7 GHz-band was fabricated by forming junction inductors on one side of the ferrite substrate and series resonant network for wideband on another side. The ferrite substrate of the circulator is as small as 14 x 14 ram. The circulator has a 20 dB isolation bandwidth of greater than 500 MHz centering at 1-7 GHz and an insertion loss of less than 1.3 dB. Before fabrication the basic relation of different junction pattern to the eigenvalue for in-phase and rotating excitation was measured and it was found that there was a part of inductance which did not participate in the nonreciprocal coupling and some distributed capacitance. The result was included in the design of the circulator and it was confirmed that rotating and in-phase eigenvalue of the circulator could be adjusted independently of one another by parallel capacitors and series resonant network for wideband, respectively. Ferrite substrate used is Ca V ferrite with a saturation magnetization of 250 ~ 500 G. Interdigital capacitors and strip inductors are made of evaporated Cr-Au and plated Au films by mean of microwave IC technique including wire bonding for crossover. A simplified approach to hybrid thermal design. R. Y. SCAPPLE and F. Z. KEISTER. Solid St. Technol. (Oct. 1973). p. 51. With the ever increasing requirements for higher power hybrids, thermal design considerations and a means for thermal analysis have become mandatory. A simplified method for analyzing the thermal resistance between a power dissipating element in a hybrid package and the package case is described. Methods for minimizing thermal resistance and for partitioning power elements are also discussed. Finally, some examples are given comparing calculated thermal resistances with actual resistances for various hybrid packaging designs. The results obtained using this simplified analysis are normally somewhat conservative. but for all practical purposes adequate for most hybrid applications.
Integrated M O S distributed RC networks for frequency selective circuits. S. M. BozIc. C. A. MILt,ER and R. I. SALAWU. Microelectron. & Reliab. 12, 139 (1973). A method of fabricating distributed RC networks for producing frequency selective circuits in IC form is proposed. An