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C-V characteristics of metal-titanium dioxide-silicon capacitors
234
World Abstracts on Microelectronics and Reliability
thickness, grain diameter, as well as the coefficients of surface scattering and grain boundary scattering. The derived formulae are compared with the results achieved by other authors.
A channel conductance measuring technique for determining the interface properties of a SiO-lnSb thin film transistor. A. VAN CALSTER.Solid-St. Electron. 21,393 (1978). A smallsignal method to determine the interface properties of a thin film transistor is described for the frequency range of 10Hz to 100KHz. By measuring the in-phase and outphase change of the channel conductance due to a small a.c. gate voltage, one can identify the possible nature of the surface states and their time, constants. This method has been applied to a SiO-InSb thin film transistor and the results obtained indicates that the interface states are, most likely, located in the SiO, and that these states can follow an a.c. signal of 7.6 KHz.
Electrocomp, Sci. Technol. 5, 107 (1978). Thin films are composed of many crystallites. Where such films are used in the construction of devices it is frequently necessary to grow them with a preferred orientation. A quick, non destructive method to measure the degree of orientation could provide a useful guide to device performance. We have investigated a technique to obtain this information using the Philips P.W. 1050/25 diffractometer. The method depends on being able to tilt the film out of the diffracting plane of the diffractometer and can be used for films in which all crystallites are orientated to better than _ 25 °, of the preferred direction. This limit is generally acceptable since greater misorientation will normally produce a poor device. The axial beam divergence of the diffractometer is shown to limit the accuracy of the technique for very highly orientated films, Experimental verification of the method is described.
Hybrid
A screening technique for establishing the stability of metal film resistors. A. P. GOSWAMI, L. SATYANARAYANA and N. V. M. SlVAJI. Electrocomp. Sci. Technol. 5, 71 (1978). A technique has been designed whereby stability data for metal film resistors may be predicted within 24 hours. Regressional analysis and statistics are used in the technique.
Size and grain-boundary effects in the electrical conductivity of thin monocrystulline films. C. R. TELLIER. Electrocomp. Sci. Technol. 5, 127 (1978). By assuming that the scattering processes from other sources than grain-boundaries can be described by a single relaxation time z* and then by solving a Boltzmann equation in which grain-boundary scattering is accounted for, we have obtained an analytical expression for the thin monocrystalline film conductivity in terms of the reduced thickness k and the grain-boundary reflection coefficient r. Numerical tables are given to show the agreement of the above expression with the MayadasShatzkes expression.
Single hybrid package houses 12-bit data-acquisition system. WAYNE E. MARSHALL. Electronics p. 113 (22 June 1978). Handling either 8 differential or 16 single-ended inputs, device acquires data at 50kHz or faster from many SOUrCes.
Effects of annealing on gap states in amorphous Si films. S. HASEGAWA,S. YAZAKIand T. SHIMIZU. Solid St. Commun. 26, 407 (1978). Annealing behaviors of the activation energy for electrical conduction, the optical gap, and the spin density in amorphous Si are investigated. It is found that the Fermi level shifts downwards with the decrease of the spin density, increasing the decay length of the wave function of localized state at the Fermi level. The downward shift of the Fermi level suggests that the localized states in the upper energy region in the gap are annealed out more easily than these in the lower one.
A hybrid thin-film logic circuit using gallium arscnide field effect transistors. R, A. STARTIN and A. C. CROSS. Electrocomp. Sci. Technol. 5, 1i3 (1978). High speed systems demand faster logic than current silicon bipolar technology can offer. Hybrid or monolithic circuits using gallium arsenide FETs provide an answer. The FETs require careful handling if electrical or mechanical damage is to be avoided. The problems of bonding a large number of these devices to a thin-film circuit to produce a working hybrid logic element are discussed. Techniques for their solution are given with reference to a completed experimental hybrid circuit.
An X-Ray technique for evaluating the structure of films for device applications. R. N. CLARKE and IAN N. COURT.
circuit includes transformer. RICHARD W. COMERFORD. Electronics p. 135 (6 July 1978). Isolation amplifier measures only 1.1 inch on a side, yet can withstand 8 kV; maximum nonlinearity is 0.1%. Variable microelectronics inductors. NABIL SALEH. IEEE Trans. Components, Hybrids, Manufacturing Technology CHMT-1, (1) 118 (March 1978). A thin-film microelectronic inductor is proposed. It is suitable for use in the frequency range from 5 to 20MHz. The inductor is in the shape of a square spiral and is surrounded by patterned permalloy thin films. The pattern allows these films to be driven in their easy axes of magnetization by the highfrequency signal current. In the presence of a small d.c. magnetic field applied in the hard direction and equal to the anisotropy field, the resulting permeability is very high, and thus the inductance of the pattern is greatly increased. Since the inductance is a function of the d.c. magnetic field applied in the hard direction, variable inductors and tunable planar resonant circuits are readily implemented using the proposed device. The design considerations of the device are described, and the significance of the theoretical results is discussed. Experimental work is being carried out to verify the above results. C - V characteristics of metal-titanium dioxide-silicon capacitors. W. D. BROWN and W. W. GRANNEMANN. SolidSt, Electron. 21, 837 (1978). Titanium dioxide capacitors were fabricated on silicon wafers using electron-beam evaporation. The TiO2 films varied in thickness from 500 to 2000A. Post-deposition oxidation at 1000°C in dry O2 was used to promote stoichiometric conversion of the films to the rutile phase. Capacitive densities of greater than 2 pf/sq, mil were obtained (dielectric constants ranged from 4 to 40). For long oxidation times, significant silicon dioxide grows under the TiO2 as a result of oxygen diffusing through the TiO2 film. Titanium was also shown to diffuse into the silicon during the oxidation cycle resulting in an n-type diffusion. Surface state densities ranging from 1011 to 5 × 101~cm-~eV -1 at midgap were obtained for good devices. Longer oxidation times result in lower capacitance, leakage current and surface state density.
Applications of reactive plasma practical microelectronic processing systems. R. L. MADDOX and H. L. PARKER. Solid St. Technol. p. 107 (April 1978). Reactive plasma etching of typical silicon MOS IC processing materials is compared to commonly used wet chemical methods. Operational characteristics (e.g. etch rates and etched edge profiles) are presented for a typical production oriented type of plasma etcher/stripper. Plasma photoresist stripping is discussed and MOS gate contamination data is presented.
Spectroscopic analysis of r.f. plasmas. W. R. HARSHBARGER and R. A. PORTER. Solid St. Technol. p. 99 (April 1978).
World Abstracts on Microelectronics and Reliability
thickness, grain diameter, as well as the coefficients of surface scattering and grain boundary scattering. The derived formulae are compared with the results achieved by other authors.
A channel conductance measuring technique for determining the interface properties of a SiO-lnSb thin film transistor. A. VAN CALSTER.Solid-St. Electron. 21,393 (1978). A smallsignal method to determine the interface properties of a thin film transistor is described for the frequency range of 10Hz to 100KHz. By measuring the in-phase and outphase change of the channel conductance due to a small a.c. gate voltage, one can identify the possible nature of the surface states and their time, constants. This method has been applied to a SiO-InSb thin film transistor and the results obtained indicates that the interface states are, most likely, located in the SiO, and that these states can follow an a.c. signal of 7.6 KHz.
Electrocomp, Sci. Technol. 5, 107 (1978). Thin films are composed of many crystallites. Where such films are used in the construction of devices it is frequently necessary to grow them with a preferred orientation. A quick, non destructive method to measure the degree of orientation could provide a useful guide to device performance. We have investigated a technique to obtain this information using the Philips P.W. 1050/25 diffractometer. The method depends on being able to tilt the film out of the diffracting plane of the diffractometer and can be used for films in which all crystallites are orientated to better than _ 25 °, of the preferred direction. This limit is generally acceptable since greater misorientation will normally produce a poor device. The axial beam divergence of the diffractometer is shown to limit the accuracy of the technique for very highly orientated films, Experimental verification of the method is described.
Hybrid
A screening technique for establishing the stability of metal film resistors. A. P. GOSWAMI, L. SATYANARAYANA and N. V. M. SlVAJI. Electrocomp. Sci. Technol. 5, 71 (1978). A technique has been designed whereby stability data for metal film resistors may be predicted within 24 hours. Regressional analysis and statistics are used in the technique.
Size and grain-boundary effects in the electrical conductivity of thin monocrystulline films. C. R. TELLIER. Electrocomp. Sci. Technol. 5, 127 (1978). By assuming that the scattering processes from other sources than grain-boundaries can be described by a single relaxation time z* and then by solving a Boltzmann equation in which grain-boundary scattering is accounted for, we have obtained an analytical expression for the thin monocrystalline film conductivity in terms of the reduced thickness k and the grain-boundary reflection coefficient r. Numerical tables are given to show the agreement of the above expression with the MayadasShatzkes expression.
Single hybrid package houses 12-bit data-acquisition system. WAYNE E. MARSHALL. Electronics p. 113 (22 June 1978). Handling either 8 differential or 16 single-ended inputs, device acquires data at 50kHz or faster from many SOUrCes.
Effects of annealing on gap states in amorphous Si films. S. HASEGAWA,S. YAZAKIand T. SHIMIZU. Solid St. Commun. 26, 407 (1978). Annealing behaviors of the activation energy for electrical conduction, the optical gap, and the spin density in amorphous Si are investigated. It is found that the Fermi level shifts downwards with the decrease of the spin density, increasing the decay length of the wave function of localized state at the Fermi level. The downward shift of the Fermi level suggests that the localized states in the upper energy region in the gap are annealed out more easily than these in the lower one.
A hybrid thin-film logic circuit using gallium arscnide field effect transistors. R, A. STARTIN and A. C. CROSS. Electrocomp. Sci. Technol. 5, 1i3 (1978). High speed systems demand faster logic than current silicon bipolar technology can offer. Hybrid or monolithic circuits using gallium arsenide FETs provide an answer. The FETs require careful handling if electrical or mechanical damage is to be avoided. The problems of bonding a large number of these devices to a thin-film circuit to produce a working hybrid logic element are discussed. Techniques for their solution are given with reference to a completed experimental hybrid circuit.
An X-Ray technique for evaluating the structure of films for device applications. R. N. CLARKE and IAN N. COURT.
circuit includes transformer. RICHARD W. COMERFORD. Electronics p. 135 (6 July 1978). Isolation amplifier measures only 1.1 inch on a side, yet can withstand 8 kV; maximum nonlinearity is 0.1%. Variable microelectronics inductors. NABIL SALEH. IEEE Trans. Components, Hybrids, Manufacturing Technology CHMT-1, (1) 118 (March 1978). A thin-film microelectronic inductor is proposed. It is suitable for use in the frequency range from 5 to 20MHz. The inductor is in the shape of a square spiral and is surrounded by patterned permalloy thin films. The pattern allows these films to be driven in their easy axes of magnetization by the highfrequency signal current. In the presence of a small d.c. magnetic field applied in the hard direction and equal to the anisotropy field, the resulting permeability is very high, and thus the inductance of the pattern is greatly increased. Since the inductance is a function of the d.c. magnetic field applied in the hard direction, variable inductors and tunable planar resonant circuits are readily implemented using the proposed device. The design considerations of the device are described, and the significance of the theoretical results is discussed. Experimental work is being carried out to verify the above results. C - V characteristics of metal-titanium dioxide-silicon capacitors. W. D. BROWN and W. W. GRANNEMANN. SolidSt, Electron. 21, 837 (1978). Titanium dioxide capacitors were fabricated on silicon wafers using electron-beam evaporation. The TiO2 films varied in thickness from 500 to 2000A. Post-deposition oxidation at 1000°C in dry O2 was used to promote stoichiometric conversion of the films to the rutile phase. Capacitive densities of greater than 2 pf/sq, mil were obtained (dielectric constants ranged from 4 to 40). For long oxidation times, significant silicon dioxide grows under the TiO2 as a result of oxygen diffusing through the TiO2 film. Titanium was also shown to diffuse into the silicon during the oxidation cycle resulting in an n-type diffusion. Surface state densities ranging from 1011 to 5 × 101~cm-~eV -1 at midgap were obtained for good devices. Longer oxidation times result in lower capacitance, leakage current and surface state density.
Applications of reactive plasma practical microelectronic processing systems. R. L. MADDOX and H. L. PARKER. Solid St. Technol. p. 107 (April 1978). Reactive plasma etching of typical silicon MOS IC processing materials is compared to commonly used wet chemical methods. Operational characteristics (e.g. etch rates and etched edge profiles) are presented for a typical production oriented type of plasma etcher/stripper. Plasma photoresist stripping is discussed and MOS gate contamination data is presented.
Spectroscopic analysis of r.f. plasmas. W. R. HARSHBARGER and R. A. PORTER. Solid St. Technol. p. 99 (April 1978).