Breakdown field strength

Em is limited by the breakdown field strength Ebd of silicon, which is about 3x 105 V cm4. The figure on the inner front cover shows the width of the SCR as a function of doping density and applied bias, as well as the limitation by avalanche breakdown. 

An n-type electrode is under reverse bias in this anodic regime, and so only a small dark current density in the order of a few pA cm-2 is observed, as shown in Fig. 4.11. The dark current increases by orders of magnitude if the breakdown field strength is reached at the electrode surface or at a pore tip present in the electrode, as discussed in Section 8.4. 

An anodic oxide grown in pure water at 10 pA cm-2 to thicknesses between 4 and 10 nm and subsequently annealed at 700 °C in N2 for 1 hour, showed an interface charge density (1011 eV 1 cnT2) and a dielectric breakdown field strength (11-14 MV cm-1) that are comparable with known values for thermal oxides [Ga2]. While the breakdown field strength of anodic oxides is comparable to thermal... 

The present work is a report of the properties of polyimide which define functionality as an interlevel dielectric/passivant. Thus, the planarizing and patterning characteristics and electrical characteristics of current vs voltage, dissipation, breakdown field strength, dielectric constant, charge and crossover isolation are discussed in addition to the reliability-related passivation properties. 

Insulation Integrity. Insulation integrity is a function of an interlayer dielectric/passivant defined by specific electrical, mechanical and passivation properties. The D.C. electrical property of interest is the I-V characteristic which is used to deduce conductivity and breakdown field strength. The corresponding A.C. electrical property is dissipation factor. The pertinent mechanical and passivation properties are, respectively, pinhole density and performance rating as a diffusion barrier to Na" " and H2O. 

The breakdown field strength is a thickness dependent property, a probable reflection of pinhole density variation with thickness. For a typical value of Interlevel dielectric film thickness (1 - 2 p), the breakdown field strength is 1 - 2.5 x 10 V/cm which is adequate for most applications. 

Thickness and, correspondingly, capacitance variation was less than 2%. The absence of impurity peaks in XPS spectra of silica-coated specimens clearly demonstrates the achieved purity. Yield, defined as the percentage of functioning vs. total measured capacitors, was 100%. Breakdown field strength was in the range 1.1-5.4 MV/cm and leakage current was about lO -lO A/cm at 0.5 MV/cm. Capacitance density was 23-350 nF/cm dependent on thin film thickness and materials. No breakdown was observed after 20 cycles between 0-40 V. Time dependent dielectric breakdown (TDDB) was 185 s at 40 V for ten of the patterned capacitors. 

FIGURE 3.28. Breakdown field strength of anodic oxide films as a function of the water content of the electrolyte during constant anodic anodization. After Mende et (Reproduced by permission of The Electrochemical Society, Inc.)... 

Varistors are electric components with variable resistance, depending on the electric current. Varistors should have low breakdown field strength combined with fairly high non-linearity of electrical conductivity. Special varistor powdered filler was prepared to obtain these properties. ... 

A minimum breakdown voltage and a minimum breakdown field strength of about no kV/cm occurred at a density of 3 g/ml (Figures 23 and 24). The effect of the electrode polarity was quantitatively similar, but the breakdown voltage for the positive spherical electrode was lower than for the corresponding flat electrode. The dielectric strength was practically independent of specimen thick-... 

Figure 24. Breakdown field strength as a function of density [35],...

The anodisation of aluminium is a well-established process [6-10]. For the formation of barrier aluminium oxide films, commonly used electrolytes are citric acid, tartaric acid and ammonium adipate [11]. Barrier films with high capacitance values and breakdown field strength were obtained in tartaric acid ofpH7[8, 12]. 

The electrical properties of the films were determined on aluminium/insu-lator/gold (MIM) structures. The capacitance was measured with a LCR Meter (Agilent 4284 A) at a frequency of 1 kHz. The specific resistance and the breakdown field strength were measured using a Source-Measure-Unit (SMU, Keithley 6430). The film thickness was determined by scanning electron microscopy (SEM). 

The anodisation factor can be considered as an indicator for the quality of the aluminium oxide films. In particular, the barrier aluminium oxide films formed with low anodisation factors exhibit high breakdown field strengths... 

The breakdown field strength was approximately 8 MV/cm. The high capacitance (430. .. 470nF/cm ) and resistivity (1.3. .. 2.4 lO ficm) of the barrier aluminium oxide film were determined. The leakage current density... 

This applicability of equations 1-4 has been verified for many types of cells and lipid vesicles by fluorescence imaging techniques (7-9) and for the measurement of critical breakdown field strength (10-12). 

PTBA also exhibits excellent strain fixity (ability to retain its actuated shape upon cooling) and strain recovery. In its softened state PTBA also possesses excellent actuation properties with a breakdown field strength in excess of 250 MV/m, a maximum strain of 335% in area, a maximum actuation stress of 3.2 MPa and an energy density of 1.2 J cm , values that rival even the best of the conventional dielectric elastomer materials. The BSEP is the first active material that possesses bistable actuation with high strain and specific power density. 

Since E > Eq = 3 x 10 V/m (breakdown field strength) discharge is to be expected. The results for other distances between the slabs are given in Table 4.14. ... 

Fig. 6.19 shows the results of the breakdown field strength of the synthetic elastomer with different contents of DOP and Ti02. The pure synthetic elastomer shows a breakdown field strength of 36.52 MV/m. When the content of the DOP is increased, the breakdown field strength of the synthetic elastomer is reduced as is shown in Fig. 6.19(a). This can be explained by the fact that when the content of the DOP increases, the dissipation factor also increases and the synthetic elastomer has a lower breakdown field field... 

Sharbaugh, 1960) proposed a thermal mechanism for the liquid breakdown which involves the formation of a bubble or a region of lower density. Under typical conditions of pulse breakdown of alkanes, a breakdown field strength of about 1.6 MV/cm is measured. An enhancement of the electric field strength at the tips of asperities of 5 is assumed. The local current density is of the order of 10 A cm". The specific local power input, Vf oc, is then given as... 

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