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Force between metallic films at small separation
World Abstracts on Microelectronics and Reliability explain this phenomenon is proposed. The effect of encapsulants has not been considered and these will offer varying degrees of protection depending on the form used.
The squeegee in printing of electronic circuits. G. C. DUBEY. Microelectron. and Reliab. 14, 427 (1975). The squeegee is an important tool in screen printing of thick-film circuits to control the uniformity in print thickness (which subsequently controls the component values). The present paper compares the various materials and shapes of squeegee used in screen printing. It has been shown that polyurethane of considerable hardness and modulus in square edge shape is the best material for use as a squeegee in off-contact printing. Resistor loops in hybrid circuits. P. L. SWART and J. D. VAN WVK. Microelecmmics 7 (3), 53 (1976). Resistor configurations containing loops or rings are encountered frequently in hybrid thick- or thin-film circuits. Configurations having simply interconnected loops are discussed. From measurements between adjacent nodes in the resistor ring a set of experimental resistive values may be obtained. It is shown how the ring elements may be calculated with this input by employing iterative techniques. Techniques for rapid convergence are discussed. The technique has been applied via an existing mini-computer CAMAC-interface data acquisition system capable of testing rings with up to 32 resistive elements. The fast convergence and consequent high speed of the method is well suited to application in an automatic trimming system and a quality control line. Sophisticated techniques solve ink manufacturing problems. DR. WILLIAMA. VITRIOLand PHILIP M. HODGE. Solid-State Teehn. p. 33 (March 1976). Helipot Division of Beckman Instruments, Inc., a manufacturer of thick-film components, develops its own material formulations and has total control over them. Its materials are developed to fit specific requirements; therefore, total characterization and complete reproducibility are necessary. As the complexity of circuits and number of materials increase, a more com-
271
plete characterization is demanded. Equipment is presently used which gives a total picture of the chemical and physical properties at hand. The same equipment that is used for giving a complete characterization of materials can also be used for problem solving. It is the purpose of this paper to show, using several examples, how having total control over thick-film material properties can give a distinct advantage in solving process and material problems through the use of developmental tools.
Preparation of thin metallic films of aluminium, lanthanum and dysprosium with minimum oxidation. M. VULLI. Vacuum 26 (3), 105 (1976). Thin films of aluminium, lanthanum and dysprosium were prepared by evaporation of the metals in a nitrogen atmosphere at pressures of about 10-6 torr. Photoelectron spectra of samples indicated a minimum of surface oxidation as compared to those obtained under similar conditions with residual gas atmosphere. Arguments for nitrogen preventing the formation of oxide during evaporation are discussed. Force between metallic films at small separation. J. HEINRICHS and N. KUMAR. Solid-State Commun. 18, 961 (1976). An exact expression for the force between two dissimilar metal films in the limit of vanishing separation is derived in terms of bulk properties of the metals. This force is compared with the results of an approximate numerical treatment of Ferrante and Smith for finite separations between the films. Thin-film circuits in transmission equipment. C. A. SCHIPPER. Philips Telecommun. Rev. 34 (1), 38 (April 1976). This article gives a review of the significance of hybrid thin-film circuits for tranmission equipment and it provides the salient points of the specifications and technology needed. Furthermore, an elaboration is given of how a model shop for hybrid circuits, used as an in-house facility, may support the electrical development. Especially direct contacts between electronic engineers and technologists could lead to optimal designs and relatively short lead times.
9. ELECTRON, ION AND LASER BEAMS Electron beams help shape better circuits. DONALD R. HERRIOT. Bell Labs. Rec. p. 69. A beam of electrons is the basis of a lower cost, faster and more precise way for making the master patterns from which the Bell System's integrated circuits are produced. Development d'un modele theorique d'evolution de surfaces soumises au bombardement ionique pour applications a la gravure. M. CANTAGREL.Microelectron. and Reliab. 14, 419 (1975). The results of a study of the theoretical model of the evolution of the geometry of a surface subjected to ionic bombardment have been described. They show that in the particular case of the vertical side of a design in the form of a boundary that the latter is very rapidly transformed into an inclined slope. The study of the phenomenon and in particular the value of the angle of slope and the rate of lateral displacement occurring in this case have enabled two characteristic parameters of the behaviour of an ionic engraving mask to be defined: (a) 6: the time necessary for the complete development of the oblique sides, (b) VR: the lateral displacement rate of the side obtained. The values of these two parameters have been measured on various materials in the case of a bombardment with argon ions of 1 keV erosion energy striking the surface with a normal incidence.
The influence of the angle of incidence of the bundle of ions on the value of the two parameters has been studied from the theoretical point of view and verified in the case of a network having 0.6 #m pitch in the glass.
Laser set-up makes high-resolution IC masks in Sweden. Electronics. (April 29 1976). Minicomputer-guided beam cuts submicrometer lines for LSls within an hour at half the usual price. C V characteristics of ion implanted depletion IGFETs and buried channel CCDs. G. W. TAYLOR. Solid-State Eh, ctronics. 19, 495 (1976). Capacitance voltage measurements of ion implanted devices for several circuit connections are presented and interpreted in terms of a simple constant profile approximation. Based on this model the device capacitance is described quantitatively in terms of the series combination of a p-n junction capacitance and a conventional MOS capacitance. It is shown that shallow and deep implants reveal characteristically distinctive C V curves which provide an immediate rough estimate of the implant depth. Analysis of the model yields directly, important parameters for first order design purposes. It is also shown that the measurements provide a simple diagnostic technique to examine the physics of the implanted structure. The use of the simplified model is justified by the agreement between experimental and calculated values.
The squeegee in printing of electronic circuits. G. C. DUBEY. Microelectron. and Reliab. 14, 427 (1975). The squeegee is an important tool in screen printing of thick-film circuits to control the uniformity in print thickness (which subsequently controls the component values). The present paper compares the various materials and shapes of squeegee used in screen printing. It has been shown that polyurethane of considerable hardness and modulus in square edge shape is the best material for use as a squeegee in off-contact printing. Resistor loops in hybrid circuits. P. L. SWART and J. D. VAN WVK. Microelecmmics 7 (3), 53 (1976). Resistor configurations containing loops or rings are encountered frequently in hybrid thick- or thin-film circuits. Configurations having simply interconnected loops are discussed. From measurements between adjacent nodes in the resistor ring a set of experimental resistive values may be obtained. It is shown how the ring elements may be calculated with this input by employing iterative techniques. Techniques for rapid convergence are discussed. The technique has been applied via an existing mini-computer CAMAC-interface data acquisition system capable of testing rings with up to 32 resistive elements. The fast convergence and consequent high speed of the method is well suited to application in an automatic trimming system and a quality control line. Sophisticated techniques solve ink manufacturing problems. DR. WILLIAMA. VITRIOLand PHILIP M. HODGE. Solid-State Teehn. p. 33 (March 1976). Helipot Division of Beckman Instruments, Inc., a manufacturer of thick-film components, develops its own material formulations and has total control over them. Its materials are developed to fit specific requirements; therefore, total characterization and complete reproducibility are necessary. As the complexity of circuits and number of materials increase, a more com-
271
plete characterization is demanded. Equipment is presently used which gives a total picture of the chemical and physical properties at hand. The same equipment that is used for giving a complete characterization of materials can also be used for problem solving. It is the purpose of this paper to show, using several examples, how having total control over thick-film material properties can give a distinct advantage in solving process and material problems through the use of developmental tools.
Preparation of thin metallic films of aluminium, lanthanum and dysprosium with minimum oxidation. M. VULLI. Vacuum 26 (3), 105 (1976). Thin films of aluminium, lanthanum and dysprosium were prepared by evaporation of the metals in a nitrogen atmosphere at pressures of about 10-6 torr. Photoelectron spectra of samples indicated a minimum of surface oxidation as compared to those obtained under similar conditions with residual gas atmosphere. Arguments for nitrogen preventing the formation of oxide during evaporation are discussed. Force between metallic films at small separation. J. HEINRICHS and N. KUMAR. Solid-State Commun. 18, 961 (1976). An exact expression for the force between two dissimilar metal films in the limit of vanishing separation is derived in terms of bulk properties of the metals. This force is compared with the results of an approximate numerical treatment of Ferrante and Smith for finite separations between the films. Thin-film circuits in transmission equipment. C. A. SCHIPPER. Philips Telecommun. Rev. 34 (1), 38 (April 1976). This article gives a review of the significance of hybrid thin-film circuits for tranmission equipment and it provides the salient points of the specifications and technology needed. Furthermore, an elaboration is given of how a model shop for hybrid circuits, used as an in-house facility, may support the electrical development. Especially direct contacts between electronic engineers and technologists could lead to optimal designs and relatively short lead times.
9. ELECTRON, ION AND LASER BEAMS Electron beams help shape better circuits. DONALD R. HERRIOT. Bell Labs. Rec. p. 69. A beam of electrons is the basis of a lower cost, faster and more precise way for making the master patterns from which the Bell System's integrated circuits are produced. Development d'un modele theorique d'evolution de surfaces soumises au bombardement ionique pour applications a la gravure. M. CANTAGREL.Microelectron. and Reliab. 14, 419 (1975). The results of a study of the theoretical model of the evolution of the geometry of a surface subjected to ionic bombardment have been described. They show that in the particular case of the vertical side of a design in the form of a boundary that the latter is very rapidly transformed into an inclined slope. The study of the phenomenon and in particular the value of the angle of slope and the rate of lateral displacement occurring in this case have enabled two characteristic parameters of the behaviour of an ionic engraving mask to be defined: (a) 6: the time necessary for the complete development of the oblique sides, (b) VR: the lateral displacement rate of the side obtained. The values of these two parameters have been measured on various materials in the case of a bombardment with argon ions of 1 keV erosion energy striking the surface with a normal incidence.
The influence of the angle of incidence of the bundle of ions on the value of the two parameters has been studied from the theoretical point of view and verified in the case of a network having 0.6 #m pitch in the glass.
Laser set-up makes high-resolution IC masks in Sweden. Electronics. (April 29 1976). Minicomputer-guided beam cuts submicrometer lines for LSls within an hour at half the usual price. C V characteristics of ion implanted depletion IGFETs and buried channel CCDs. G. W. TAYLOR. Solid-State Eh, ctronics. 19, 495 (1976). Capacitance voltage measurements of ion implanted devices for several circuit connections are presented and interpreted in terms of a simple constant profile approximation. Based on this model the device capacitance is described quantitatively in terms of the series combination of a p-n junction capacitance and a conventional MOS capacitance. It is shown that shallow and deep implants reveal characteristically distinctive C V curves which provide an immediate rough estimate of the implant depth. Analysis of the model yields directly, important parameters for first order design purposes. It is also shown that the measurements provide a simple diagnostic technique to examine the physics of the implanted structure. The use of the simplified model is justified by the agreement between experimental and calculated values.