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IBM Journal of Research and Development

Issue 5 • Date Sept. 1969

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Displaying Results 1 - 25 of 32
  • Editor's Note

    Publication Year: 1969 , Page(s): 486
    Save to Project icon | PDF file iconPDF (167 KB)  
    Freely Available from IEEE
  • A Perspective on Acoustoelectric Instabilities

    Publication Year: 1969 , Page(s): 487 - 493
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (725 KB)  

    The acoustoelectric instabilities appear in diverse forms and seem complex because of the large number of factors which influence them. A perspective on the instabilities is provided in terms of experiments on the III–V semiconductors, selected to limit or control the variables. Detailed evidence is presented that the source of the acoustic flux is the thermal equilibrium phonon spectrum. T... View full abstract»

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  • Parametric Amplification and Frequency Shifts in the Acoustoelectric Effect

    Publication Year: 1969 , Page(s): 494 - 498
    Cited by:  Papers (2)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (528 KB)  

    Mechanisms for the downshift in the frequency of maximum acoustic intensity fmi for high flux domains in piezoelectric semiconductors are reviewed. For the simple case where an externally introduced acoustic wave (pump) produces a single-frequency domain in photoconducting CdS, clear evidence is given that the downshift in fmi is due to parametric amplification of thermal aco... View full abstract»

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  • A Brillouin Scattering Study of Acoustoelectric Domain Formation in n-GaAs

    Publication Year: 1969 , Page(s): 499 - 502
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (421 KB)  

    Brillouin scattering measurements in n-GaAs show (1) that the initial formation of acoustoelectric domains is the consequence of spatially inhomogeneous amplification produced by resistivity inhomogeneities, and (2) that the subsequent stages of domain evolution involve flux-dependent processes which further shape the domain; an important process appears to be parametric frequency conversion. View full abstract»

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  • Off-axis Acoustoelectric Domains in CdS

    Publication Year: 1969 , Page(s): 503 - 506
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (435 KB)  

    In CdS crystals oriented with the electric drift field parallel to the c axis, acoustoelectric domains consist of off-axis shear waves. This is because there is no acoustoelectric gain for shear waves traveling along the hexagonal axis, while the gain may be large in an off-axis direction. The particular angle at which the gain is a maximum depends on the angular dependence of the electromechanica... View full abstract»

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  • Acoustoelectric Amplification in InSb

    Publication Year: 1969 , Page(s): 507 - 509
    Cited by:  Papers (2)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (401 KB)  

    It was demonstrated by Kikuchi that two modes of acoustoelectric domain oscillation occur in InSb in a transverse magnetic field. Using lithium niobate transducers on an acoustic amplifier, we have measured linear acoustic gain as a function of electric and magnetic field and frequency. At high magnetic fields (B ≥ 3000 gauss) the results are in good agreement with White's theory. However, ... View full abstract»

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  • Characteristics of Semiconducting Glass Switching/Memory Diodes

    Publication Year: 1969 , Page(s): 510 - 514
    Cited by:  Papers (3)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (606 KB)  

    Semiconducting glass diodes can exhibit at least three conducting states: a high-resistance, or “off” state; a low-resistance, or “on” state; and a negative resistance state. When appropriately pulsed they can also display a memory function. The laboratory operation of simple diodes and the methods of inducing transitions among the various states are described. In addit... View full abstract»

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  • Physics of Instabilities in Amorphous Semiconductors

    Publication Year: 1969 , Page(s): 515 - 521
    Cited by:  Papers (3)  |  Patents (2)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (687 KB)  

    A four-fold classification of the current-controlled instabilities in amorphous semiconductors is proposed. The experimental evidence supporting a simple band model for the amorphous covalent alloys is given. The present understanding of the reversible switching effects and of the switching with memory is discussed. View full abstract»

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  • Current Filaments in Semiconductors

    Publication Year: 1969 , Page(s): 522 - 528
    Cited by:  Papers (2)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (704 KB)  

    A current filament is a non-uniform radial distribution of current in the presence of a uniform electric field in a uniform sample. These filaments can have diameters in the 0.005 inch range. The current density at the center of the filament can be several orders of magnitude higher than the background current density in the rest of the sample. Filaments have been studied in devices exhibiting the... View full abstract»

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  • Current Oscillations in Deep-level Doped Semiconductors

    Publication Year: 1969 , Page(s): 529 - 532
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (490 KB)  

    We observe current oscillations in p-i-n (and optically excited n-i-n) devices containing deep levels. The oscillations occur in the positive resistance region of the space-charge-limited (SCL) current regime of the I–V characteristics, before the occurrence of double-injection breakdown. This is a general effect, occurring in Si, Ge, and GaAs compensated with various deep-level impurities ... View full abstract»

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  • Space-charge-limited Current Instabilities in n+-π-n+ Silicon Diodes

    Publication Year: 1969 , Page(s): 533 - 536
    Cited by:  Papers (3)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (464 KB)  

    If the strength of a pulsed electric field of about 103 volts/cm is exceeded in a nickel-doped 25,000 ohm-cm π-type silicon sample with n+ contacts, a transient charge distribution is established that leads to a current instability. When the critical applied field is reached a current-controlled negative resistance is observed. The sample impedance decreases by several... View full abstract»

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  • Time Response of the High-field Electron Distribution Function in GaAs

    Publication Year: 1969 , Page(s): 537 - 542
    Cited by:  Papers (22)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (663 KB)  

    Numerical calculations have been made of the high-field electron distribution function for GaAs, its small-signal frequency response and its behavior in large sinusoidal electric fields. The response speed is limited by the low scattering rate within the 〈000〉 valley. With increasing frequency the threshold field for negative conductivity rises and the negative mobility and oscillato... View full abstract»

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  • Negative Conductivity Effects and Related Phenomena in Germanium. Part I

    Publication Year: 1969 , Page(s): 543 - 553
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (1063 KB)  

    This paper is the first part of a two-part review of recent work on current instabilities and related properties of germanium in high electric fields. In this part we discuss the general subject of high field transport in n-Ge with emphasis on the concept of saturated drift velocity. The oscillations which result from bulk negative differential conductivity (BNDC) in [100] and [110] directions at ... View full abstract»

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  • Negative Conductivity Effects and Related Phenomena in Germanium. Part II

    Publication Year: 1969 , Page(s): 554 - 561
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (686 KB)  

    This paper is the second part of a two-part review of recent work on current instabilities and related properties of germanium in high electric fields. In this part the transferred carrier mechanism for producing bulk negative differential conductivity (BNDC) in a semiconductor is discussed. Experimental work on instabilities related to three realizations of this effect, in uniaxially compressed n... View full abstract»

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  • Bulk Negative Differential Conductivity in Germanium: Theory

    Publication Year: 1969 , Page(s): 562 - 567
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (618 KB)  

    Two mechanisms have been proposed for the bulk negative differential conductivity of n-type germanium first observed by Elliott et al. These are discussed with reference to recent Monte Carlo calculations in which effects due to intravalley acoustic phonon scattering, 〈100〉 and 〈000〉 minima and ellipsoidal constant energy surfaces are explored. Strong evidence is presen... View full abstract»

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  • Wave Propagation in Negative Differential Conductivity Media: n-Ge

    Publication Year: 1969 , Page(s): 568 - 572
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (425 KB)  

    A study has been made of transverse electromagnetic wave propagation in the negative differential resistance medium provided by suitably oriented n-type germanium at 77°K. The wave frequency is chosen to fall below the critical scattering rates in this system (1 GHz), and the sample dimensions are maintained below the critical length for domain formation. Thus when the electric vector is or... View full abstract»

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  • Trap-controlled Field Instabilities in Photoconducting CdS Caused by Field-quenching

    Publication Year: 1969 , Page(s): 573 - 579
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (631 KB)  

    The formation of stationary high-field domains adjacent to cathode or anode, dependent on the contact potential of the electrodes, their widening with increased applied voltage and their transition into two types of moving domains are discussed. Domains which move under deformation of the domain profile and usually dissolve before they reach the anode, and nearly undeformed moving domains are desc... View full abstract»

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  • The Effects of Hydrostatic Pressure on Hot-electron Phenomena in n-InSb

    Publication Year: 1969 , Page(s): 580 - 582
    Cited by:  Papers (2)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (423 KB)  

    The effect of hydrostatic pressure on the Gunn effect (high pressures) and bulk avalanche breakdown (low pressures) in n-InSb is studied. The measured generation rates of electron-hole pairs at 77°K and 195°K at several pressures are compared with the theory of Dumke. View full abstract»

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  • Location of the 〈111〉 Conduction Band Minima in the GaxIn1−xSb Alloy System

    Publication Year: 1969 , Page(s): 583 - 586
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (522 KB)  

    Pressure dependence of the resistivity and optical absorption by conduction band electrons are used to determine the position of the 〈111〉 (L1) conduction bank minima in the GaxIn1−xSb alloy system. These experimental data permit a more precise estimate of the position of the L1 minima than had been possible using Gunn effect data al... View full abstract»

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  • The Influence of Boundary Conditions on Current Instabilities in GaAs

    Publication Year: 1969 , Page(s): 587 - 590
    Cited by:  Papers (14)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (499 KB)  

    We obtain excellent agreement among experiments eliciting a variety of GaAs current instabilities and the results of a computer simulation of GaAs with various fields imposed at the cathode boundary. When the cathode field is below around 4 kV/cm theory and experiments show that the I–V characteristics of the active element are linear up to about 3 kV/cm where the current saturates and no t... View full abstract»

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  • A Topological Theory of Domain Velocity in Semiconductors

    Publication Year: 1969 , Page(s): 591 - 595
    Cited by:  Papers (2)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (525 KB)  

    A theory is given for the velocity of a free, steadily travelling domain of high electric field in a semiconductor exhibiting a negative differential conductivity. Explicit results are derived for the cases for which the domain behavior is dominated either by the (electric-field dependent) diffusion of electrons, or by the rate of transfer of electrons between states having different mobilities. I... View full abstract»

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  • Avalanche Shock Fronts in p-n Junctions

    Publication Year: 1969 , Page(s): 596 - 600
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (570 KB)  

    The conditions necessary for the formation of avalanche shock fronts, narrow layers of avalanche moving through a diode depletion layer faster than the carrier saturated drift velocity, are shown to be related to the large-signal limits of Read and more general avalanche transit time diode theory. Analysis of shock fronts by a simple analytic method has been used to interpret computer simulations ... View full abstract»

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  • Coherent Microwave Emission from an Electron-hole Plasma

    Publication Year: 1969 , Page(s): 601 - 606
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (606 KB)  

    Coherent microwave radiation, 6.5 to 44 GHz, is generated by InSb at 77°K with an injected electron current transverse to a magnetic field. The maximum output power is about 10 microwatts for input power levels of one to five watts. Grooves cut into the Suhl surface of the rod-shaped InSb samples impose the coherence and determine the frequency range of coherent operation. Wavelength measur... View full abstract»

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  • Negative Differential Mobility in Nonparabolic Bands

    Publication Year: 1969 , Page(s): 607 - 610
    Cited by:  Papers (1)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (440 KB)  

    A strong NDM (negative differential mobility) in n-InSb at low temperatures is predicted from a single non-parabolic band model. Calculations allowing for the anisotropy of the distribution function have been made using (1) a drifted Maxwellian, and (2) a “two-temperature” model. The calculated NDM threshold field of 550 V/cm is in an observable field range in p-n junctions. In bulk ... View full abstract»

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  • The Role of Acoustic Wave Amplification in the Emission of Microwave Noise from InSb

    Publication Year: 1969 , Page(s): 611 - 615
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (482 KB)  

    The experimental evidence for the generation of microwave emission from InSb by acoustic amplification of thermal noise is reviewed. The conditions in which the electron-phonon interaction is likely to dominate over other possible physical mechanisms are discussed, with particular reference to crystallographic orientation and crystal geometry. The application of the small signal acoustic amplifica... View full abstract»

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Aims & Scope

The IBM Journal of Research and Development is a peer-reviewed technical journal, published bimonthly, which features the work of authors in the science, technology and engineering of information systems.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Clifford A. Pickover
IBM T. J. Watson Research Center