Poly sensitivity curves

Figure 12. Sensitivity curve for 0.8 im thick chlorinated poly(styrene) resist exposed at 248 nm and developed for 21 mins, by O2 RIE.

Figure 7. Sensitivity curves for brominated samples of poly(TMSP) film thickness, —300 nm 260 nm. Sample designations are explained in the caption...

Fig. 156 Deep UV sensitivity curves of thermal development of poly(4-trimethylsilyl)-phthalaldehyde containing 1.2 and 4.8 wt% TPSOTf [334]...

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...

As expected, the incorporation of pendant unsaturation in the resists greatly enhances sensitivity as demonstrated by a comparison of the contrast curves for poly(N-aiiyl maleimide-VBC) and the structurally similar poiy(N-ethyl maleimide-VBC) (Figure 4). Both polymers have similar molecular weights and nearly identical mass absorption coefficients but the allyl-containing copolymer is 5X faster. 

The effect of increased x-ray absorption on sensitivity was explored by conducting monochromatic exposures of a bromine-containing resist, poly(N-allyl maleimide-vinyl benzyl bromide), at photon energies which bracket the bromine absorption edges between 1.6 and 1.8 keV contrast curves obtained for these monochromatic exposures are shown in Figure 7. The results are also plotted as l/D "5 vs absorption coefficient in Figure 8 the data accurately follow the predicted inverse relationship defined by Equation 1. 

It was found that preliminary ultraviolet irradiation alters the photoelectrical sensitivity. Figure 23 represents the spectral response curves for the photoconductivity (curve 1) and the photoelectromotive force (curve 3) of poly (PiP -diethynylazobenzene). 

A calibration curve for glucose at a UMB with poly( 1,3-DAB) is shown in Figure 3. The calibration curve is piece-linear. The linearity over the normal human clinical range for glucose (3-7 mM) is good (r=0.998), and the sensitivity is 9.2 pA/mM. The calibration curve levels off at about 15-20 mM glucose, due to oxygen limitation. 

The effect of electrode fouling was tested by obtaining calibration curves at two UMBs, one with enzyme and poly( 1,3-DAB), and one with enzyme only. Both UMBs were then placed in a 3% w/v BSA solution in pH=7.4 buffer, for 6 h, at T=4°C. After 6 h, the UMBs were removed, rinsed, and calibration curves were again obtained. The sensitivity of the UMB with polymer film decreased by 10%, some of which can be attributed to experimental error. The sensitivity of the UMB without polymer film decreased over 30%. 

Films of PMMA with 20 to 30% poly(epi-chlorohydrin) require only 1/2 to 1/4 the exposure to produce patterns compared to PNNA alone. Thinning-exposure curves also suggest a sensitivity increase of 3 or 4 times. Contrast suffers somewhat, but patterns are producible when a nitride-supported gold mask is used. 

The TGA curve indicates a complex decomposition process. The Py-GC/MS result for poly[4,4 -hexafluoro-isopropylidene)-diphthalic anhydride-aff-acridine yellow G] HCI is given in Figure 13.4.3. This is a light sensitive polymer (X max. 273 nm) but also with high heat resistance, and the pyrolysis was performed at 850 C in He. Other conditions were kept similar to those for other examples previously described (see Table 4.2.2). The separation was done on a Carbowax column. The peak identification was done using MS spectral library searches only and is given in Table 13.4.4. 

Eig. 4 Sensitivity characteristic curve of poly(silamine) IV developed by methanol, (Thickness 5,000 A) (Reproduced from ref. 4 by courtesy of publishers, Hiitig and Wepf, Zug,... 

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