Resist processes

The third approach employs modifications of the polymer s physical properties and/or resist processing to minimize contaminant absorption, and is described in the section, "Polymer Properties and Lithographic Performance". 

In other work, the impact of thermal processing on linewidth variation was examined and interpreted in terms of how the resist s varying viscoelastic properties influence acid diffusion (105). The authors observed two distinct behaviors, above and below the resist film s glass transition. For example, a plot of the rate of deprotection as a function of post-exposure processing temperature show a change in slope very close to the T of the resist. Process latitude was improved and linewidth variation was naininiized when the temperature of post-exposure processing was below the film s T. 

It is more difficult to produce pure wool easy care garments. The problem is to obtain adequate durability of the setting rather than obtaining shrink-resistance, because some wool setting processes are not stable to machine washing. As of ca 1997, the best approach is to combine the Synthappret BAP fabric shrink-resist process with Siroset garment setting. 

Shrink-resistance processes compatible with Zirpro-treated wool have also been developed (166). 

The selection of basis material, conversion coating, and paint formulation is an art based upon experience. The variables that are typically involved in the selection are appearance, color, gloss, corrosion resistance, abrasion resistance, process line capability, availability of raw materials, customer preference, and cost. Some basis materials inherently work better with certain conversion coatings, and some conversion coatings work better with certain paint formulations. On the whole, however, the choice of which combination to use on a basis material is limited only by plant and customer preferences.1-4... 

Whilst elimination (by oxidation) or masking (by polymer deposition on the cuticular scales) are the accepted mechanisms by which shrink resistance is achieved, there is evidence that other factors need to be considered, particularly as it is possible to obtain a shrink-resist effect without degradation or masking of the scales. A review is available [310] of the mechanism of chlorine-based shrink-resist processes. 

Table 10.34 Relative amounts of sulphur oxidation products formed during shrink-resist processing of wool [11,311]...

The particular requirements of shrink-resist processes in relation to wool fabric printing have been described [312]. In addition to dimensional stability, there is a need for ease of... 

Onsager s theorem deals with reciprocal relations in irreversible resistive processes, in the absence of magnetic fields [114], The resistive qualifier signifies that the fluxes at a given instant depend only on the instantaneous values of the affinities and local intensive parameters at that instant. For systems of this kind two independent transport processes may be described in terms of the relations... 

In general, any linear resistive process is described by the equation... 

Recently, nonionic acid precursors based on nitrobenzyl ester photochemistry have been developed for chemically amplified resist processes (78-80). These ester based materials (Figure 8) exhibit a number of advantages over the onium salt systems. Specifically, the esters are easily synthesized, are soluble in a variety organic solvents, are nonionic in character, and contain no potential device contaminants such as arsenic or antimony. In addition, their absorption characteristics are well suited for deep-UV exposure. 

Organosilicon polymers are especially important as imaging layers in bilayer resist processes(1). A wide range of organosilicon resist materials, in which the organosilicon compound has been incorporated either into the polymer main chain or into pendant groups, has appeared in the literature(2-8). However, almost all polymers have been... 

Figure 13 Schematic representation of the bilevel resist process employing an oxygen reactive ion etching pattern transfer technique.

Figure 16 Schematic representation of a vapor phase functionalized resist process.

Figure 44. A schematic representation of the plasma developed x-ray resist process. Exposure serves to covalenty bind the monomer (m) into the polymer matrix (p). Heating (fixing) drives out (volatilizes) the monomer except where it is "locked in place" by exposure. Plasma treatment converts the silicon to Si02 which retards the etch rate in the exposed areas through formation of a metallic oxide (MO) layer.

Figure 1. Flow chart for a typical resist process. Steps in broken lines are not used for all materials.

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