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Thin films of nickel oxide and their application in thin-film triodes
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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
Thin films of nickel oxide and their application in thin-film triodes. A. E. FEUERSANGER,Proc. 1967 Electron. Compon. Conf., Washington, DC, p. 104. This paper describes the preparation of insulating and semiconducting films of nickel oxide and their application in a new space-charge-limited (SCL) triode. Thin films of nickel oxide prepared by thermal oxidation and by reactive sputtering of high-purity nickel on oxygen were investigated. The thickness of the nickel oxide films were in the range betwccn 0"1 and 2 microns. The films prepared by thermal oxidation of evaporated nickel were insulating with resistivites relatively independent of the partial pressure of oxygen. The properties of the sputtered films were very sensitive t o sputtering conditions. With high current densities, insulating fihns were also obtained; however, with the same oxygen pressure, a decrease in the sputtering current density by a factor of five produced a decrease in the resistivity by a factor of one thousand. The current-voltage characteristic of a number of films revealed distinct regions of conduction, ohmic, space-charge limited (SCL) and double injection. The mobility of the nickel oxide films under space-charge-limited conditions is 23 cm2/V.s. This result indicates that 2p hole conductivity is involved as suggested by Morin. With the use of sputtered nickel oxide films of widely different conductivities, thin-film triodes were prepared with the defect- or semiconducting-oxide as the chalmel and the the nearly stoichiomctric oxide as the insulator in a planar geometry. The transistors exhibited triode-type characteristics with a transconductance of 650 tz ohms at a drain voltage of 8.7 V. The conduction carriers in the senticonducting nickel oxide are holes as is indicated by the enhancement mode of operation. From the transistor parameters and dimensions, an effective mobility of 23 cm'°/V.s was determined, in agreement with the results from the SCL mode. Several samples were prepared with TiO 2 films as the dielectric.
Batch fabrication of thin film resistors for hybrid circuitry by electroless deposition of nickel phosphide. M. A. FOLEY, Proc. 1967 Electron. Compon. Conf., Washington, DC, p. 422. Thin films of nickel phosphide have been produced on unglazed ceramic substrates and glass epoxy laminates which have resulted in uniform, stable and highly predictable resistive elements. Flexibility of processing permits selection of a variety of substrate materials and resistor-conductor combinations. Lowtemperature chemical reduction processing and the ease and accuracy of adjusting resistor values by surface abrasion permit production with uncomplicated equipment. By employing standard photolithographic techniques, large numbers of multiple circuit arrays can be generated with a precision not easily achieved with present silk-screening operations. The high-yield and large-volume potential of the process lends itself well to unique applications, such as resistive arrays for read-only computer memory devices, high-power miniature resistive elements on ceramics, and precision resistors in integrated circuit fabrication. Wide ranges of sheet resistivity (1 ohm to 2000 ohms/square) are available with associated temperature coefficients of less than 100 p p m [ C and power ratings of 10 W/in 2 of active resistor area. The m e c h a n i s m of conduction in thick-film cermet resistors. L. J. BRADY. Proc. 1967 Electron. Compon. Conf., Washington, DC, p. 238. This study concerns the conduction mechanism of thick-film cermet resistors. These resistors may be thought of as a composite of resistive or conductive elements, arranged in jack-straw fashion, bounded to each other to give electrical conduction, and to a ceramic substrate by means of a vitreous binder. This model requires the observed resistance to equal the resistance of elemental resistors and the construction resistance observed at the points of contact between them. The use of this model to interpret the effects of thermally induced strains on the constriction resistance led to the devclopment of mathematical expressions which give an insight into the conduction mechanism of cermet resistors. These expressions arc presented, and it is shown that they apply to thick-film cermet resistors whose resistive components are metallic in nature as well as to those which intrinsically exhibit narrow-band semiconductive behavior. Bidirectional electrochemical trimming of thick film resistors. J. A. O'CoNNELL, E. A. ZARATKIEWICZand H. J. CURNAN,Proc. 1967 Electron. Compon. Conf., Washington, DC, p. 247. Thick film resistors are prepared by screen printing specially prepared resistive inks on alumina substrates. Resistor characteristics are then established by an air firing at an elevated temperature. Resistor design is governed by the simple relationships given. At the present state-of-the-art, a very broad range of resistance values can be obtained, but because of the nature of the screening and physical variables such as the change of viscosity of resistor inks, screen wear, etc., most people can consistently deposit resistors
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
Thin films of nickel oxide and their application in thin-film triodes. A. E. FEUERSANGER,Proc. 1967 Electron. Compon. Conf., Washington, DC, p. 104. This paper describes the preparation of insulating and semiconducting films of nickel oxide and their application in a new space-charge-limited (SCL) triode. Thin films of nickel oxide prepared by thermal oxidation and by reactive sputtering of high-purity nickel on oxygen were investigated. The thickness of the nickel oxide films were in the range betwccn 0"1 and 2 microns. The films prepared by thermal oxidation of evaporated nickel were insulating with resistivites relatively independent of the partial pressure of oxygen. The properties of the sputtered films were very sensitive t o sputtering conditions. With high current densities, insulating fihns were also obtained; however, with the same oxygen pressure, a decrease in the sputtering current density by a factor of five produced a decrease in the resistivity by a factor of one thousand. The current-voltage characteristic of a number of films revealed distinct regions of conduction, ohmic, space-charge limited (SCL) and double injection. The mobility of the nickel oxide films under space-charge-limited conditions is 23 cm2/V.s. This result indicates that 2p hole conductivity is involved as suggested by Morin. With the use of sputtered nickel oxide films of widely different conductivities, thin-film triodes were prepared with the defect- or semiconducting-oxide as the chalmel and the the nearly stoichiomctric oxide as the insulator in a planar geometry. The transistors exhibited triode-type characteristics with a transconductance of 650 tz ohms at a drain voltage of 8.7 V. The conduction carriers in the senticonducting nickel oxide are holes as is indicated by the enhancement mode of operation. From the transistor parameters and dimensions, an effective mobility of 23 cm'°/V.s was determined, in agreement with the results from the SCL mode. Several samples were prepared with TiO 2 films as the dielectric.
Batch fabrication of thin film resistors for hybrid circuitry by electroless deposition of nickel phosphide. M. A. FOLEY, Proc. 1967 Electron. Compon. Conf., Washington, DC, p. 422. Thin films of nickel phosphide have been produced on unglazed ceramic substrates and glass epoxy laminates which have resulted in uniform, stable and highly predictable resistive elements. Flexibility of processing permits selection of a variety of substrate materials and resistor-conductor combinations. Lowtemperature chemical reduction processing and the ease and accuracy of adjusting resistor values by surface abrasion permit production with uncomplicated equipment. By employing standard photolithographic techniques, large numbers of multiple circuit arrays can be generated with a precision not easily achieved with present silk-screening operations. The high-yield and large-volume potential of the process lends itself well to unique applications, such as resistive arrays for read-only computer memory devices, high-power miniature resistive elements on ceramics, and precision resistors in integrated circuit fabrication. Wide ranges of sheet resistivity (1 ohm to 2000 ohms/square) are available with associated temperature coefficients of less than 100 p p m [ C and power ratings of 10 W/in 2 of active resistor area. The m e c h a n i s m of conduction in thick-film cermet resistors. L. J. BRADY. Proc. 1967 Electron. Compon. Conf., Washington, DC, p. 238. This study concerns the conduction mechanism of thick-film cermet resistors. These resistors may be thought of as a composite of resistive or conductive elements, arranged in jack-straw fashion, bounded to each other to give electrical conduction, and to a ceramic substrate by means of a vitreous binder. This model requires the observed resistance to equal the resistance of elemental resistors and the construction resistance observed at the points of contact between them. The use of this model to interpret the effects of thermally induced strains on the constriction resistance led to the devclopment of mathematical expressions which give an insight into the conduction mechanism of cermet resistors. These expressions arc presented, and it is shown that they apply to thick-film cermet resistors whose resistive components are metallic in nature as well as to those which intrinsically exhibit narrow-band semiconductive behavior. Bidirectional electrochemical trimming of thick film resistors. J. A. O'CoNNELL, E. A. ZARATKIEWICZand H. J. CURNAN,Proc. 1967 Electron. Compon. Conf., Washington, DC, p. 247. Thick film resistors are prepared by screen printing specially prepared resistive inks on alumina substrates. Resistor characteristics are then established by an air firing at an elevated temperature. Resistor design is governed by the simple relationships given. At the present state-of-the-art, a very broad range of resistance values can be obtained, but because of the nature of the screening and physical variables such as the change of viscosity of resistor inks, screen wear, etc., most people can consistently deposit resistors