Development rate characterization

This gives two choices ia interpreting calculated NRR values, ie, a direct comparison of NRR values for different options or a comparison of the NRR value of each option with a previously defined NRR cutoff level for acceptabiUty. The NPV, DTC, and NRR can be iaterpreted as discounted measures of the return, iavestment, and return rate, analogous to the parameters of the earher example. These three parameters characterize a venture over its entire life. Additional parameters can be developed to characterize the cash flow pattern duting the early venture years. Eor example, the net payout time (NPT) is the number of operating years for the cumulative discounted cash flow to sum to zero. This characterizes the early cash flow pattern it can be viewed as a discounted measure of the expected operating time that the investment is at risk. 

Computerized real-time measurements and analysis of the coefficient of friction, contact high-frequency acoustic emission, and pad wear allow the effective evaluation of consumables, understanding of tribological interactions at the polishing interface, process development, dynamic characterization of the polishing process, including rate and nonuniformity of material removal, and so on. The application of tribometrology not only is restricted to research and development departments but also proves very useful in the device production facilities. 

It is evident that, in order to elucidate the copolymerization kinetics, extensive and systematic experimentation is required to provide data on the initiation, termination and propagation rates. The major stumbling block in the acquisition of experimental data has been, besides the normal difficulties associated with polymer experimentation, the lack of efficient characterization techniques which can yield reliable quantitative information on the MWD, CCD, and SLD or at least some of their leading moments. Such information is of primary importance in the elucidation of copolymerization kinetics. It is, therefore, felt that a major effort aimed at the study of copolymerization kinetics and at the development of characterization techniques is clearly justified. 

There are a number of reasons that it is important to characterize the dissolution or development rate of any given resist. The main reasons tend to be for process control purposes, given that image discrimination in resists is based on differences in dissolution rates between the image and non-image areas. The two main techniques that are used to characterize the dissolution properties of a resist are laser interferometry and quartz crystal microbalance. Each of these techniques is reviewed below. 

Numerous microscale devices and techniques have been developed to characterize the flow behavior of polymer solutions. The principal motivation for this broad class of techniques is to enable characterization of tiny liquid volumes for which samples are costly or difficult to obtain in large quantities. These microfluidic rheometers fall into three categories, organized in order of increasing De devices to measure intrinsic viscosity, shear-rate-dependent viscosity, and non-Newtonian behavior for a range of flow types. 

The Vicat softening temperature is the temperature at which a flat-ended needle of 1-mm circular cross section will penetrate a thermoplastic specimen to a depth of 1 mm under a specified load using a selected uniform rate of temperature rise. This test is very similar to the deflection temperature under the load test and its usefulness is limited to quality control, development, and characterization of materials. The data obtained from this test is also useful in comparing the heat-softening qualities of thermoplastic materials. However, the test is not recommended for flexible PVC or other materials with a wide Vicat softening range. 

Since then, more advanced imaging modalities have been developed to characterize these small lesions. However, the scope of the problem has dramatically increased as the number of small focal lesions detected by helical and MDCT and MR has increased substantially. In early studies with spiral CT scanning increased the detection rate for small lesion on 74%-85% (Valls et al. 2001 Ward et al. 1999). In these series almost all the false-negative... 

Thin film dissolution behavior has been the subject of stuity for many applications. In the case of positive photoresists, a number of techniques have been used to characterize the kinetics of dissolution (1-12). The earliest such e q>eriments were performed by exposing the resist to a solvent for a fixed time and then measuring the thidmess of the remaining film (2). From repeated measurements of this type, a bulk development rate could be determined. 

More recently Andrews and Juzeliunas [6, 7] developed a unified tlieory that embraces botli radiationless (Forster) and long-range radiative energy transfer. In otlier words tliis tlieory is valid over tire whole span of distances ranging from tliose which characterize molecular stmcture (nanometres) up to cosmic distances. It also addresses tire intennediate range where neitlier tire radiative nor tire Forster mechanism is fully valid. Below is tlieir expression for tire rate of pairwise energy transfer w from donor to acceptor, applicable to transfer in systems where tire donor and acceptor are embedded in a transparent medium of refractive index ... 

The mathematical machinery needed to compute the rates of transitions among molecular states induced by such a time-dependent perturbation is contained in time-dependent perturbation theory (TDPT). The development of this theory proceeds as follows. One first assumes that one has in-hand all of the eigenfunctions k and eigenvalues Ek that characterize the Hamiltonian H of the molecule in the absence of the external perturbation ... 

The power law developed above uses the ratio of the two different shear rates as the variable in terms of which changes in 17 are expressed. Suppose that instead of some reference shear rate, values of 7 were expressed relative to some other rate, something characteristic of the flow process itself. In that case Eq. (2.14) or its equivalent would take on a more fundamental significance. In the model we shall examine, the rate of flow is compared to the rate of a chemical reaction. The latter is characterized by a specific rate constant we shall see that such a constant can also be visualized for the flow process. Accordingly, we anticipate that the molecular theory we develop will replace the variable 7/7. by a similar variable 7/kj, where kj is the rate constant for the flow process. 

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