High-voltage pulse stressing of thick-film resistors and noise

In this paper the results from a study of high-voltage pulse stressing effects on resistance and low-frequency noise of thick-film resistors based on two different resistor compositions with sheet resistances of 10 and 100 kΩ/sq are presented. For the experimental purposes thick-film test resistors of different dimensions were realized and exhibited to voltage pulses with 1500 and 3000 V amplitudes. Obtained experimental results are qualitatively analyzed from the microstructure, charge transport mechanism and low-frequency noise aspects. Correlation between resistance and low-frequency noise changes with resistor degradation due to high-voltage pulse stressing is observed. It is shown that low-frequency noise is more sensitive to this kind of resistor stressing than resistance and that measured values of noise index are in agreement with resistance noise spectrum results.     

Low-frequency noise in thick-film resistors due to two-steptunneling process in insulator layer of elemental MIM cell

In this paper, it is assumed that low-frequency noise source in thick-film resistors are fluctuations of the trap occupations by electrons, tunneling through insulator layer of the elemental cell. Two conducting particles separated by a thin insulating layer form the elemental cell (MIM structure). Trap charge fluctuations are modulating the MIM cell barrier, thus modulating the tunneling current and barrier resistance. A low frequency noise model is proposed under the assumption that the space distribution of traps in thick-film resistor is symmetrical with respect to the central plane of the MIM cell. Numerical results show that in the presence of small number of traps in insulator layer of the elemental cell, 1/f noise is exhibited in a narrow frequency range (4-5 decades). A model is applied on the experimental results for noise in thick-film resistors and a method of evaluation of the trapping state's parameters is discussed based on noise measurements     

Physical model of burst noise in thick-film resistors

A physical model for burst-noise generation in thick-film resistors is presented. The noise is attributed to fluctuations of tunneling current flowing through a conductive metal particle chain containing a marginally conductive insulation layer located in a high-field region of the resistor. The fluctuation of the tunneling current is controlled by a change in the charge state of a single generation-recombination center located in the marginally conductive insulation layer. This model is used to explain the observed dependence of the burst-noise pulse amplitude on the biasing current and the dependence of the pulse widths on temperature.     

Low-frequency noise in thick-film structures caused by traps in glass barriers

In this paper a model of low-frequency noise in thick-film structures based on the close relationship of the noise and conduction mechanisms is presented. The emphasis is placed on the presence of traps in thin, glass barriers as the least studied source of low-frequency noise in thick-film structures under conditions of dominant tunneling current flow. The influence of contacts between some of the adjacent conducting particles on noise is discussed. From numerical simulation, fitting the experimental results and theoretical curve based on the proposed model, we found that the noise is sensitive to the thick-film structure.     

Excess noise as an indicator of digital integrated circuit reliability

Excess noise measurements have been performed on CMOS logic integrated circuits. The noise has been observed in the power supply leakage current with no gates switching and in the dynamic power supply current when gates are switched. The presence and size of the noise has been shown to be a sensitive indicator of the quality and hence reliability of the device.     

半导体激光器的低频电噪声谱密度和器件的可靠性

本文给出了半导体激光器的低频电噪声谱密度和器件可靠性关系的实验结果。     

Simultaneous mechanical and electrical straining of conventional thick-film resistors

In this paper results from the study of simultaneous mechanical and electrical straining effects on performances of conventional thick-film resistors based on three different resistor compositions with sheet resistances of 1 kΩ/sq, 10 kΩ/sq and 100 kΩ/sq are presented. For experimental purposes thick-film test resistors of different dimensions were realized. Resistors were simultaneously subjected to mechanical straining with maximal substrate deflection of 300 μm and multiple high-voltage pulses. Obtained experimental results are analyzed from micro- and macrostructural, charge transport and low-frequency noise aspects. Correlations between resistance, gauge factor and low-frequency noise changes with resistor degradation due to simultaneous mechanical and electrical straining are observed.     

Hydrostatic high pressure studies of polymer thick-film resistors

The behaviour of carbon black/polyesterimide thick-film resistors under high hydrostatic pressure (up to 5000 bar) and at the temperature range from 20 to 150°C is presented. The gradual resistance decrease observed with pressure increase is dependent on carbon black kind and contents. Much higher compressibility of polymer matrix than active phase affects gradual increase of carbon black volume fraction. The basic relationship of percolation theory, ρ∝(v_CB−v_CBc)^−t, is used successfully for semi-quantitative analysis of high pressure effect on tested devices. It is shown that this effect is temperature independent.     

Multiple high-voltage pulse stressing of conventional thick-film resistors

In this paper, results from a study of multiple high-voltage pulse (MHVP) stressing effects on resistance and low-frequency noise of thick-film resistors based on resistor compositions with sheet resistances of 1, 10 and 100 kΩ/sq are presented. For experimental purposes, a series of thick-film test resistors with identical geometries were realized and exhibited to two types of tests: multiple series of 10 pulses with increasing amplitudes from the 0.5 to 4.0 kV range and multiple series of 10 pulses with constant 3 kV and 4.5 kV amplitudes. Obtained experimental results were analyzed and correlation between resistance and low-frequency noise changes with resistor degradation due to MHVP stressing was observed. Comparing the resistance and noise index changes it is shown that low-frequency noise parameters are more sensitive to this kind of resistor stressing than resistance. During high-voltage pulse stressing, certain number of resistors failed and progressive resistor degradation that led to catastrophic failure is also presented in this paper.     

Evaluation of conductive-to-resistive layers interaction in thick-film resistors

Low-frequency noise spectroscopy is used to examine the interactions between resistive and conductive films that take place during thick-film resistor (TFR) fabrication. Two noise parameters are introduced to quantitatively describe the strength of these interactions. They refer to intensity and repeatability of the noise generated in the resistor interfaces. Extensive experimental studies performed on ruthenium dioxide and bismuth ruthenate TFRs terminated with gold, platinum–gold, palladium–silver and platinum–silver contacts from various manufacturers allow to establish criteria of pastes compatibility and to evaluate compatible systems of pastes for standard “on-alumina” and low-temperature co-fired ceramic (LTCC) resistors. It is found that gold contacts form low-size-effect, stable, low-noise interfaces both with ruthenium dioxide and bismuth ruthenate TFRs. Silver-containing terminations can be used with bismuth ruthenate but not with ruthenium dioxide resistors. Manufacturer optimized system of pastes for LTCC technology works best when used to produce high-resistive, co-fired devices.     

Noise properties of thick-film resistors in extended temperature range

Results of thorough experimental studies on electrical properties of thick-film resistors (TFRs) have been overviewed and summarized. Experiments covered resistance and noise measurements in wide temperature range. Low-frequency noise spectroscopy has been used for the investigations of fluctuating phenomena. Sample resistors were prepared of various combinations of commercial and laboratory-made conducting and resistive pastes and printed on alumina substrates. Resistive pastes were made of materials: (i) Pb-containing RuO₂- and Bi₂Ru₂O₇-based, (ii) Pb/Cd-free RuO₂-, CaRuO₃-, and RuO₂/CaRuO₃-based. Conducting pastes included Ag, Ag-Pd and Ag-AgPt-Pd, Au, PtAu as a main ingredients. Electrical properties of various TFRs made of different materials were compared. Cross-correlation technique of noise spectra measurements in conjunction with the multiterminal configuration of TFRs was used in investigations of noise vs. resistor volume, resulting in extraction of noise components originated in different parts of the resistor. Furthermore, noise of the resistor was split up into bulk and interface noise. Resistance noise, observed in all studied TFRs, has been found to consist of background 1/f noise and Lorentzian noise induced by thermally activated noise sources (TANSs). Properties of TANSs have been described and their relation to TFRs performance parameters have been pointed out. Noise properties of various Pb-containing and Pb/Cd-free resistive materials have been compared with the use of bulk noise intensity parameter, C_bulk. Conclusions concerning compatibility of resistive and conductive pastes have been formulated. They might be useful in further improvement of materials systems for thick-film technology in order to fabricate low-noise and stable passives.     

Stability of low ohmic thick-film resistors under pulsed operation

Durability of low ohmic thick-film resistors on pulse load with micro- and millisecond duration are described in this paper. Standard thick-film resistive compositions with sheet resistance of 10 Ohms/sq. (4311 and QS871 - DuPont; R400-10A - Heraeus) and 3 Ohms/sq. (QS870 - DuPont) were tested. Test resistors with resistance of 3 Ω were prepared on alumina substrates. Resistance changes were measured after 50 pulses at each voltage. Then the voltage was increased and the series of pulses were repeated until the resistance change exceeded 0.5%.Impact of long and short pulses was analyzed for selected pulse duration of 10 μs and 20 ms, respectively. The measurements were carried out for some selected resistors length. The resistors stressed by long pulses exhibited the highest durability, when the thermal interface between substrate and heatsink was filled by thermally conductive grease. In this case resistors made of 4311 and QS871 pastes can withstand the highest power density of about 19 W/mm² and 18 W/mm² for the samples with and without the overglaze, respectively. Short (microsecond) pulses had the least influence on overglazed resistors made of QS871 paste, for which the resistance change of +0.5% was observed at electric field intensity of about 85 ± 10 V/mm.Additionally, the critical electric field intensity and critical power density were determined for different pulse duration for selected resistor length of 2 mm. Pulse duration from 10 μs to 1 s with one point per decade were taken into account. The results shown, that overglazed resistors exhibit better durability for all tested resistive pastes for short pulses. However for the long pulses, the results are almost the same. This fact can be explained by limitation of heat transfer in the substrate.Repetitive pulse load was applied for selected samples. The results show that resistors exhibited very good stability after test with 0.1 million pulses with amplitude of 70% of critical electric field intensity values.     

Low-frequency noise measurement-based reliability testing of VLSI interconnects with different geometry

Low-frequency noise measurements were performed on thin metallic very large-scale integration (VLSI) interconnects of three different geometries. These measurements were carried out under stressing current densities between 1.0/spl times/10/sup 5/ A/cm/sup 2/ and 2.2/spl times/10/sup 6/ A/cm/sup 2/ at different ambient temperatures up to 280/spl deg/C, in order to investigate the dependence of low-frequency noise on the geometrical shape of the VLSI interconnects. The behavior of these samples under these conditions is analyzed in this letter.     

Techniques of adjusting thin- and thick-film resistors in hybrid microelectronic circuits

Various techniques of adjusting thin- and thick-film resistors in hybrid microelectronic circuits are briefly described and their relative merits and shortcomings pointed out.     

1/f noise as a reliability indicator for subsurface Zener diodes

It is shown from accelerated life tests and noise measurements that the degradation in reference voltage for subsurface Zener diodes is strongly correlated with 1/f noise in the devices. The larger the initial 1/f noise of a diode is, the earlier its degradation occurs. Compared with dc parameters, 1/f noise is more sensitive to the slight change in the structure of the devices subjected to operation or test stresses. In the mechanism analysis, the degradation and the 1/f noise are attributed to similar physical origin, and both are related to dislocations in the space-charge region of p–n junction. Based on the results, a 1/f noise screening approach is proposed for the high reliability application of the devices.     

Advanced electrical and stability characterization of untrimmed and variously trimmed thick-film and LTCC resistors

As-fired thick-film resistors have the resistance tolerance within ±20% and this tolerance is increased for smaller components. Therefore the novel trimming methods are necessary for microresistors, especially when they are embedded in LTCC substrate. This paper compares electrical (normalized temperature dependence of resistance, low frequency noise) and stability properties (relative resistance drift, changes of current noise index) of untrimmed, voltage pulse trimmed and laser trimmed unglazed thick-film resistors after step-increased long-term thermal ageing at 162 °C, 207 °C and 253 °C. Moreover the effect of long term exposure (1000 h, 125 °C) and thermal shocks (1000 shocks between −55 °C and 125 °C) is analysed for untrimmed and voltage pulse trimmed buried LTCC resistors.     

Popcorn noise and generation-recombination noise observed in ion-implanted silicon resistors

Experimental results show that, for low currents, the generation-recombination noise component increases with current, and, at higher currents, it decreases inversely with current. For currents greater than a certain value, a generation-recombination noise component is scarcely observed.     

White noise in MOS transistors and resistors

The theoretical and experimental results for white noise in the low-power subthreshold region of operation of an MOS transistor are discussed. It is shown that the measurements are consistent with the theoretical predictions. Measurements of noise in photoreceptors-circuits containing a photodiode and an MOS transistor-that are consistent with theory are reported. The photoreceptor noise measurements illustrate the intimate connection of the equipartition theorem of statistical mechanics with noise calculations