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Showing papers on "Junction temperature published in 1969"


Journal ArticleDOI
TL;DR: In this paper, a non-destructive and accurate method of measuring the heat flow resistance between junction and heat sink by utilizing the temperature dependent breakdown voltage V b (T) as a conveniently built-in temperature sensor is described.
Abstract: Avalanche transit time oscillators are operating at power densities approaching 106W/cm2, unprecedented in semiconductor device history. At such power densities, heat flow resistance problems at the interface between the flip-chip mounted silicon chips and the metal substrate, as well as between the package and the heat sink, are extremely critical. This paper describes a new, nondestructive and accurate method of measuring the heat flow resistance between junction and heat sink by utilizing the temperature dependent breakdown voltage V b (T) as a conveniently built-in temperature sensor. Variations in junction temperature ΔT with power ΔP= V b ΔI are, therefore, related to variations in breakdown voltage ΔV b with current ΔI resulting in a contribution to the electrical small signal resistance of the diode. This thermal resistance contribution R th can be separated readily from spreading and space charge resistance R ap and R sc because of the frequency dependence of R th (ω). Furthermore, the frequency dependence of R th (ω) allows the separation of heat flow resistance contributions originating in the immediate vicinity of the junction (Si-metal interface) from contributions originating at a poor thermal contact between package and heat sink. In keeping with calculations on simplified geometrical configurations, for which analytical solutions of the frequency dependent heat flow in a distributed circuit could be obtained, experimental results are presented which indicate that both heat flow resistance contributions can be extracted and separated with sufficient accuracy from as few as three electrical resistance measurements, e.g., at dc, 100 Hz, and 1 MHz. The simplicity of such measurements and their evaluation make this technique ideal for in-line testing of production devices.

62 citations


Journal ArticleDOI
TL;DR: In this paper, a simple method is proposed and demonstrated for the determination of a minute amount of deep-level impurities in the transition region of p−n junctions from the high-frequency capacitance change when the junction temperature is lowered from room temperature to 77°K and the junction bias is switched to zero and back to the large reverse bias to set the charge trapped at these centers to the equilibrium value.
Abstract: A simple method is proposed and demonstrated for the determination of a minute amount of deep‐level impurities in the transition region of p‐n junctions from the high‐frequency capacitance change when the junction temperature is lowered from room temperature to 77°K and the junction bias is switched to zero and back to the large reverse bias to set the charge trapped at these centers to the equilibrium value. Sensitivity of 1011 atoms/cm3 and 105 total atoms in the depletion layer is demonstrated in junction gettered by phosphorus glass. Examples are also given for Ni‐ and Audoped silicon diodes and transistors.

36 citations


Journal ArticleDOI
01 Jun 1969
TL;DR: In this article, the gate currents of Ge and Si junction FETs operating beyond pinch-off show a component which increases as the temperature decreases and increases rapidly with drain voltage.
Abstract: The gate currents of Ge and Si junction FET's operating beyond pinch-off show a component which increases as the temperature decreases and increases rapidly with drain voltage. A model is presented which explains these currents in terms of impact ionization by majority charge carriers, accelerated to energies above 1 eV in the high field region of the pinched-off channel. The probability of carriers reaching these energies is thought to be determined by their interactions with the lattice and thus is a function of lattice temperature, carrier type, and semiconductor material.

18 citations


Patent
18 Jun 1969
TL;DR: In this article, a two-part sensor is used employing high and low metallic compound transition temperature materials for a solid-state refrigerator control circuit operating with two-point temperature control.
Abstract: Temperature sensors in pilot contact and sensor relays are comprised by first order transition materials which provide an abrupt change in at least one of the properties thereof, in particular volume, at predesigned transition temperatures in response to variations in temperature over a given range. Due to the hysteresis characteristics built into the sensors through the use of suitable first order transition materials, the transition temperature values will be different as the temperature increases from a lower to a higher temperature from the transition temperature value as the temperature decreases from a higher to a lower temperature. Preferably a two-part sensor is used employing high and low metallic compound transition temperature materials. An application is a solid state refrigerator control circuit operating with two-point temperature control.

13 citations


Journal ArticleDOI
TL;DR: In this paper, a method of determining the junction temperature under breakdown condition is described, where the applied voltage and the current are calculated from the ambient temperature T 0, where T 0 is the temperature coefficient of the Si p+n junction diodes.
Abstract: A method of determining the junction temperature under breakdown condition is described. The junction temperature T1 is calculated from the applied voltage and the current in the following equation: V1=VB0{1+β(T1-T0)}+I1ρsc0{1+γ(T1-T0)}, where V1 and I1 are the applied voltage and current, VB0 and ρsc0 are the breakdown voltage and the space charge resistance at the ambient temperature T0, and β and γ are the temperature coefficients of VB and ρsc, respectively. Based on this method, the burn-out temperatures of mesa-type Si p+–n junction diodes are found to be between 200~300°C. The cause of burn-out at such a low temperature is also discussed.

11 citations


Patent
S Fujiwara, H Hasegawa, M Iizuka, G Kano, T Sawaki 
29 Sep 1969
TL;DR: In this article, a pressure sensitive transistor whose emitter or collector junction is formed by use of a Schottky barrier junction is described, wherein the current through the transistor changes in accordance with the applied pressure when pressure is applied to said junction by pressure applying means.
Abstract: Disclosed is a pressure-sensitive transistor whose emitter or collector junction is formed by use of a Schottky barrier junction and wherein the current through the transistor changes in accordance with the applied pressure when pressure is applied to said junction by pressure applying means. Such a transistor is advantageous in that a high pressure-to-current conversion factor is obtained, little noise is generated at the junction, and the reverse leakage current appearing at the junction is extremely small.

7 citations


Patent
08 Sep 1969
TL;DR: In this article, a method and apparatus for measuring temperatures and temperature anomalies along the longitudinal axis of a borehole penetrating underground formations characterized by employing a constant current flowing through a diode junction means and measuring the variations in voltage across the junction as an indication of the temperature.
Abstract: Method and apparatus for measuring temperatures and temperature anomalies along the longitudinal axis of a borehole penetrating subterranean formations characterized by employing a constant current flowing through a diode junction means and measuring the variations in voltage across the junction as an indication of the temperature. The diode junction means is linear up to temperatures of about 350 DEG F and linear enough to be usable to temperatures as high as 400 DEG F. Signals are generated that are related by the voltage drop across the diode junction means to the temperature and transmitted to the surface where they are converted to an analog indication of temperature. The analog indication of temperature is differentiated to emphasize temperature anomalies. Specific structure of the diode junction means and a temperature compensated constant current regulator is also disclosed.

4 citations


Journal ArticleDOI
TL;DR: In this paper, a simple method for adjusting the temperature sensitive voltage data to correct for such shifts is described; the method yields valid transient thermal impedance determinations in far less time than could be realized without the correction method.
Abstract: In the course of determining the transient thermal impedance of power thyristors, step-like shifts are often observed in the temperature-sensitive voltage characteristic used to estimate the virtual junction temperature of the device. This correspondence describes investigations which have shown that these step-like shifts are in fact spontaneous voltage transients which are highly sensitive functions of current and temperature, and which cause small hysteresis effects in the voltage-current characteristics of the device. A simple method for adjusting the temperature sensitive voltage data to correct for such shifts is described; the method yields valid transient thermal impedance determinations in far less time than could be realized without the correction method.

2 citations


Journal ArticleDOI
TL;DR: In this paper, the authors studied the effect of adiabatic heating of the junction and its immediate surrounding on the shape and duration of the light output pulse in GaAs junction lasers operated with asinglerectangnlar current pulse at 300'~ both theoretically and experimentally.
Abstract: The time duration of the output pulse from a diode laser operated by a single current pulse is dependent on the rate of heating of the active region adjacent to the junction (Engeler and Garfinkel 1965). The effects of adiabatic heating of the junction and its immediate surrounding on the shape and duration of the light output pulsein GaAs junction lasers operated with asinglerectangnlar current pulse at 300'~ have recently been studied elsewhere (Broom 1968) both theoretically and experimentally. It has been observed (Broom 1968) that under adiabatic conditions, when the effects of heat diffusion away from tlle junction are neglected, the junction becomes excessively heated and tl~ertiial quenching of stimulated emission occurs in times of less than 1 psec. At room temperature, the junction temperature rise and the duration of the light output pulse in GaAs junction lasers have both been found (Broom 1968) to be functions of the drive and threshold currents. Thus it is felt by the present authors that these features of pulsed operation of GaAs junction lasers would depend also on other laser parameters which are yet to be investigated. The purpose of the present communication is to study the reflectivity dependence of the junction temperature rise and the maximum time duration of the output pulse in GaAs junction lasers operated with a single rectangular current pulse at 300% under adiabatic conditions of junction heating. The heating in jnnction lasers mostly results from the absorption of spontaneous and stimulated ,emission, the energy dissipittion by non-radiative transitions and the ohmic losses. . The relative magnitude of these sources depends upon the diode construction, the ambient temperature and the operating current density. Incidentally, it has been discussed by Broom (1.968) that under large operating currents at room temperature, the resistive heating and the heating due to non-radiative transitions are the most dominant. These dominant sources of heat dissipation lead to adiabatic heating of the junction when the thermal diffusion length I; is less than the thickness d of the active region. In GaAs diodes at 300°~, the thermal. conductivity K,? 0.5 Joules (cm degsec)-I for the n andp sides of the diode (Carlson et al. 1965),,the specific heat C = 0.32 Joules (g deg)-I (Piesbergen 1963) a!lditIle density p = 5.37 g ~m-~ , (Broom 1968). Therefore, the thermal diffusivity k, = K/Cp = 0.29 cm2 sec-I and L= d(k,t) is of the order of few microns'for a time t equal to few hundred , nanoseconds. Thus the diffusion of heat away from the junction may be ' neglected for current pulse lengths up to 200 ns or so since the thickness d of the