Mercury emission lines

Figure 19 shows the ultraviolet absorption spectrum of a typical diazonaphthoquinone and a common novolac resin. The naphthoquinone sensitizer has a strong absorbance at the 365 nm., 405 nm., and to a lesser extent the 436 nm. mercury emission lines. There are two diazonaphthoquinone isomers that are used in commercial photoresist formulations that are available at this time. The 5-arylsulfonates are by far the most commonly used. A spectrum of a representative of this class of materials is depicted in Figure 20. The 5-arylsulfonate materials are characterized by an absorbance maximum at approximately 400 nm. and a second, slightly stronger maximum at approximately 340 nm.

Figure 19. Absorbance spectrum of a typical diazonaphthoquinone sensitizer (in solution) and a cresylic acid novolac (film). The wavelengths of principle mercury emission lines are labeled.

Figure 46. The optical transmission characteristics of a UV-3 filter for the Perkin Elmer Micralign 500. The filter was designed for Mid-UV projec-tion lithography. Note that it is essentially opaque in the near and deep UV. The wave length of the major mercury emission lines are noted.

In Fig. 2, the Raman spectrum of polypropylene is shown. In this example, a 17-in. working distance objective was attached to a filter fiber-optically coupled probe. The probe was supported above the film and the probe position was adjusted so that the film was approximately in focus. In this example, it should be noted that no modification to the polymer film line was required. In addition. Fig. 2 presents the spectrum of both postex-truded molten polymer and drawn crystallized polymer. The spectra recorded on-line agreed with the published literature for polypropylene with the exception of the band at 490 cm from the 532-nm laser [16]. The bands at 490 cm are related to a mercury emission line at 546.0 nm from the room lights. The observation of this line and the laser line can be used to provide on-the-fly calibration information because these lines arise from fundamental atomic emissions therefore their frequency is invariant to the Raman... 

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