Dielectric capacitance

A transformer has both dielectric capacitances and electromagnetic inductances. Surge transference thus depends on the electrostatic and electromagnetic transient behaviour of these parameters as noted below. 

V Z./C is the surge impedance, Z, L and C the circuit constants of the interrupting circuit, as discussed in (Section 17.6.4). C represents the dielectric capacitance between the parting contacts of the interrupter. must be prevented, as far as practicable, from reaching dangerous levels with the use of surge arresters. 

The result can be simplified by making use of the above-defined pinch-off voltage [Eq. (14.54)1 and dielectric capacitance of the semiconducting layer. Further simplifications result from the assumptions that Cs 2> C, (Eq. (14.57)), and that the dopant and carrier concentrations arc equal (Eq. (14.58)). 

The drain current Id is proportional to the charge-carrier mobility the transistor dimensions, where W and L are the channel width and length respectively, the applied voltage, where Vgs and VT are the gate-source and threshold voltage, and the insulator capacitance Cj (Eq. 1). Thus, the impact of the dielectric material on transistor performance is given by the dielectric capacitance which results from a geometrical quotient of area A and distance d (distance is the film thickness of the dielectric layer) and a material factor where s0 and er are the dielectric constant in a vacuum and of the material, respectively (Eq. 2). As consequences of these correla-... 

For future high-speed microelectronic devices, copper interconnection with low dielectric constant (low-k) interlayer films is required to decrease RC (R interconnect resistance, C interlayer dielectric capacitance) delay. Recently, porous Si02 and silica-based films, developed for low-k films, have been extensively studied by positron annihilation spectroscopy [28], [29], [19]. Since Ps formation occurs with high probability, and the o-Ps annihilate via pick-off process in Si02-based materials, positron annihilation spectroscopy (especially PALS) gives useful information on the size of the pores. 

Majewski et al. have looked at ultrathin Si02 on metallized (aluminum metal) Mylar [32], These systems involve 60-nm aluminum on Mylar as the gate electrode, with Si02 3.5 mn ( three times the limit predicted by theory and experiments on Si02/Si). In these ultrathin Si02 dielectrics, capacitances as high as 1 TF/cm are achieved. Addition of an OTS (octyltrichlorosilane) SAM to this system reduces the... 

In the standard metal-oxide semiconductor field-effect transistor (MOSFET) drain-current equations, is a proportionality factor that relates the drain current /p, to the gate and drain voltages and V[)s, respectively the threshold voltage V, the channel width W and length L and the gate dielectric capacitance per unit area Cox. The standard drain-current equation for an -channel device in the linear region of operation - V) is [4]... 

Two approaches are proposed to resolve this difficulty. The first is based on generation of a high-purity acoustic field in a spherical, unharmonic resonator, and the second is based on comparison of a set of transducers with limited but overlapping dynamic ranges. In the second approach, simultaneous measurement of a broadband signal produces an accurate characterization over the entire range. Candidates for sensor fabrication include solid dielectric capacitive sensors, piezoelectric transducers, and high-temperature lithium niobate or quartz transducers. 

Figure 10.9.1 Equivalent circuits used to analyze the transient behavior of the toad urinary bladder membrane. Rq represents electrolyte resistance and Q is the dielectric capacitance of the membrane. The branches involving and R are used to account for the transfer of charge across the...

Dielectric constant Dielectric Capacitance constant bridge... 

Where AVt is the change in the threshold voltage, Qmouie is the mobile charge contributed from the dipole and C x is the gate dielectric capacitance. 

Test transistors allow for process monitoring and straightforward extraction of device performance. Several material parameters (such as the dielectric capacitance and the gate source/drain misalignment) can also be measured directly from a transistor. Transistors with a range of channel lengths should be included to allow for contact parameter extraction. A detailed layout is shown in Fig. C.6. 

While it is possible to measure the gate dielectric capacitance through QSCV overlap, it is advisable to include several metal/insulator/metal capacitors to allow independent measurement of the gate dielectric. The capacitors can be formed using the gate and the source/drain layers. 

The conductive path in parallel with the dielectric capacitance causes the Maxwell—Wagner surface charge. This interface single layer surface charge must not be confused with the double layer charge formed at a wet interphase. With liquid interphases such as with particles or cells in aqueous media, the double-layer counter-ion effects are additive to the Maxwell—Wagner effects. 

A capacitor consists of two conductive plates separated by a dielectric. Capacitance is directly proportional to the dielectric constant of the insulating material. Ceramic compounds doped with barium titanate have... 

Figure 6.36. Combined measurements of the gas pressure and the (real part of the) dielectric capacitance at v = 10 MHz of a capacitor filled with MSNal3X (UOP) inside a commercially operating VSA-process for air separation (Mahler AG) [6.15]. Changes in the gas pressure and the capacitance are due to ad- and desorption of nitrogen (N2) on the sorbent.

Figure 22-5. Electrical bridge (AC) for dielectric capacitance measurement.

Capacitance, Material as dielectric Capacitance, Air (or Vacuum) as dielectric... 

A of Si02, with an estimated gate dielectric capacitance of 17nFcm . Aluminum was used as the interconnect metal and the source and drain metals used was gold. 

As shown by Eqs. (4) and (5), low operating voltage requires high gate dielectric capacitance per area Q = kZo/d, where k is the dielectric constant, the permittivity of vacuum and d the thickness of the dielectric layer. Hence, there are two methods to increase the current increase the dielectric constant or decrease the thickness [26]. 

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