Exposure characteristic curves

The exposure characteristic curves were obtained by plotting normalized film thickness versus the logarithm of exposure time. Ihe improvement in resist contrast was evaluated by comparing the y-value (slope of the exposure characteristic curve) for... 

Ihe performance of the CEL layer can be evaluated from the exposure characteristic curves for the conventional photoresist (OFPR800) and the CEL/OFPR800 layer systems shown in Fig.8. The CEL layer thicknesses used in these experiments were 0.8 urn for D2, 1.0 urn for D3, and 0.5 urn for D4. A 1.0 urn thick OFPR800 layer was used as the imaging layer. 

Fig8. Exposure characteristic curves for the CFPR800 and CEL/OFPR800 systems. The film thickness of (FPR800 was 1.0um. The thickness of each CEL layer was the same as in Fig. . 

Contrast ratios can be calculated from the bleaching curve (Fig.7) and the sensitivity of the photoresist, while the. observed contrast ratios can be directry obtained from the exposure characteristic curves shown in Fig.8. The calculated contrast ratios were compared with the observed ratios in the CEL curve. The calculated values are in fair agreement with the observed values. The CEL curve is thus thought to be a useful tool for designing CEL dyes because it can predict the performance of the dyes used for CEL materials. 

Prints developed by this technique are comparable to those obtained with microcapsules. Using color density vs. exposure characteristic curves, sensitometric properties of the different formulations can be evaluated and compared. 

Fig. 9.3 Schematic representation of exposure characteristic curves for positive and negative resists. Adapted from Schlegel and Schnabel [27] with permission from Springer.

By general convention, the sensitivity, S, is related to the thickness, d, of the resist layer measured after exposure and development, and is obtained from exposure characteristic curves, as are illustrated in Fig. 9.3. In the case of positively functioning resists, S = corresponds to the exposure light dose required to completely remove the irradiated polymer from the substrate, i.e. the dose at which the normalized thickness of the resist layer is equal to zero, dirr/do=0. In the case of negatively acting resists, the sensitivity is reported as S = or... 

Figure 5. Exposure characteristic curves for the systems of 1, MB HP, DIAS (a) and of 2, BHP, DIAS (b).

Figure 3.20 Exposure characteristic curves for resists. The film thickness normalized with respect to its initial value (d/do) as a function of the exposure dose (Dexposure)-...

Most of the resists that have been employed to date are polymer-based-that is, they consist wholly or partly of an amorphous polymer. A resist material must fulfill various requirements (i) it must be suited for spin casting from solution into a thin and uniform film that adheres to various substrates and (ii) it must possess a high radiation sensitivity and a high resolution capability. Commonly, the radiation sensitivity S is defined by exposure characteristic curves (Figure 3.20). 

Fig. 20. Characteristic curves of a model Polavision image transmission density vs the relative log exposure where ( ) is the positive image (-), the...

Table IV compares the X-ray exposure characteristics (at 8.3 X, Al Kai,2 emission line) of the halogenated resists and of PMMA Elvacite 20U1. It can be seen that poly(2-ehloroethyl methacrylates) and poly(2-bromoethyl methacrylates) exhibit a low sensitivity unlike poly(2-fluoroethyl methacrylates) and poly(2-, 2-,2-trifluoroethyl methacrylates) which are more sensitive than PMMA as shown in Figures 2a, 2b, 2c, 2d where the dose-thickness curves of these resists are plotted. The low sensitivity of the PC1EMA and PBrEMA samples may be explained by some competing crosslinking reactions which could occur during exposure as a result of C-Cl and C-Br homolytic bond scissions as noted by Tada...

The exposed samples were dip-developed in appropriate mixtures of methylethylketone and ethanol, rinsed in pure ethanol and finally postbaked above their respective Tg s for 1 hr. Film thicknesses were measured optically using a Nanometrics Nanospec/AFT microarea thickness gauge. Characteristic exposure response curves were plotted as normalized film thickness remaining vs. log dose (expressed in jtC/cm2). 

A plot of the gel fraction versus exposure is referred to as a characteristic curve of the resist. The contrast of a resist film is defined as the slope of the characteristic curve, dWgei/dE at speedpoint, where E — EG, and it can be presented as... 

Lithographic Characteristics. The exposure response curves for P(SI-CMS) and Sl-novolac containing PMPS (SI-NPR) are shown in Figure 4, and their lithographic characteristics are summarized in... 

Hada et al. [89] compared experimental characteristic curves with theoretical curves based on a model of exposure and development. A marked difference in the ability of specks to initiate development was found between silver specks smaller than Ag4 and those larger than Ag4. 

Fig. 2 Typical exposure or characteristical curves, do is the maximum thickness of a resist layer (A) a negative tone photoresist (B) a positive tone photoresist.

The measured contrast is a slope of a thickness obtained vs. dose exposed curve (characteristic curve). The theoretical value of contrast is the maximum slope of a plot of the logarithm of development rate vs. logarithm of exposure energy curve. Contrast can be determined as ... 

Figure 19. Three photographic characteristic curves for a monodispersed AgBr cubic emulsion (0.5 m cube edges) bearing a low level of surface sulfur sensitization. In all cases the film was given a 10 3 s flash exposure through a photographic step tablet with a step interval of 0.15 density units. The film was then immersed for 15 min in a redox buffer of ferrous/ferric EDTA with a potential of —105.4 mv relative to bulk Ag/AgBr at the same Br concentration. It is concluded that the small silver clusters of the subdevelopable image are unexpectedly stable (56C).

The photographic emulsion properties of speed, contrast, and latitude may be obtained from the characteristic curve of the emulsion, which shows the relation that exists between exposure and the optical density of the photographic image. A typical characteristic curve is shown in Figure 6-1. If the exposure is plotted as the logarithm of exposure, the characteristic curve has a toe (AB) where the slope increases, followed by a linear portion (BC), and, finally, a region where the slope decreases (CDE) and becomes negative. The density is defined as... 

Relative speeds of different emulsions will differ, as illustrated in Figure 6-4. Emulsion II has a higher contrast constant y than emulsion I, and its inertia is greater, as indicated by /, and The choice between emulsion I or II depends on the purpose for which it is to be used. If very low intensities are to be recorded, emulsion I would be chosen because of its lower emulsion inertia. If high contrast is desired, emulsion II would be preferred. Emulsion latitude is a measure of the minimum to maximum exposure that will satisfactorily reproduce in the emulsion. It may be considered to be the exposure range of the linear portion of the characteristic curve of the emul-... 

The photocurrent increases linearly with incident light intensity, as shown in the current versus voltage (/-V) characteristic curve for a photodiode (see Figure 13.6b) however, note that saturation (i.e. no further increase in current) in photodiodes is typically reached for light exposure of 1—2 mW. 

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