Deep-UV sensitivity curves

Figure 7. Deep UV sensitivity curves of SPP positive node (A) compared with that of SPP negative mode (B). In positive mode, a 0.4 izm thick SPP layer was exposed to deep UV and then dip-developed in a 1.6 wt% TMAH solution for 60 s at 25 °C. In negative mode, SPP was exposed to deep UV followed by a flood exposure using near UV radiation and then dip-developed in a 0.7 wt% TMAH solution for 60 s at 25 C.

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

Figure 4. Deep UV sensitivity curve of tertiary alcohol resist containing 4.75 wt% PhjS -SbFg...

Figure 12. Deep UV sensitivity curves of secondary alcohol resist containing 1.5 wt% PhjS -OTf.

An electron beam exposure machine ELS-5000 (Elionix) operated at 20 kV was used for lithographic evaluation. Sensitivity curves to X-ray and deep UV (254 nm) were determined with a X-ray exposure machine SR-1 (Mo target), developed in our laboratory 12) and a Spectro Irradiator, CRM-FA (JASCO), respectively. After exposure, SNR was developed with (3/1) methylethylketone-isopropanol solvent mixture and rinsed with isopropanol. 

Plotted in Figure 7 are the sensitivity curves for brominated polymers exposed to deep-UV radiation. The samples were prepared by spin coating polished Si wafers with a 2% solution of the polymer in chlorobenzene. 

A lithographic sensitivity curve for PVTMSK is shown in Figure 6. The sensitivities for both deep-UV and mid-UV exposures were similar, although the deep-UV source emitted only —5% of its radiation at 365 nm. The range marked by an arrow denotes the radiation dose for which the partially developed film had a very rough texture. 

Figure 6. Lithographic sensitivity curve for PVTMSK exposed to deep-UV radiation. The pattern was spray developed for 10 s with 2-propanol at...

These polymers are of potential interest as photoresists, and their photochemistry was also studied in very thin (1-4 pm) films which were spun cast on polished salt plates. After irradiation in a standard xenon arc photoilluminator, the loss of carbonyl could be determined from FTIR measurements. Experiments were carried out both at 254 nm (deep UV) and 313 nm (near UV). Typical rate curves are shown in Fig. 9. The results at 254 and 313 nm are qualitatively similar, in that the same order of relative sensitivity is observed. 

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