Irradiated film

Ne+ ion irradiation of a 0.13 nm thick film produces a metallic silvery film. A plot of the infrared COO vibrations as a function of fluence in Figure 10 shows that the intensity decreases with approximately the same functional dependence as in the He ion irradiation, but at a dose that is 17 times lower. In addition, a new band appears at 1616 cm-1, peaking at a dose of — 1.7x1012 ions/cm2, then decreasing rapidly to the same level as the original acetate bands. This may represent the formation of some monodentate acetate species as the palladium acetate trimers are cleaved. In situ infrared spectra of the He ion-irradiated films show a similar band of much smaller relative intensity. 

In order to determine if the diminish of ethylenic double bond of the polymer by the attack of nitrene occurs, the ratio of IR absorbances due to v(C=C) of ethylenic double bond(3100cm-1) and due to v(CH) of alkane(2990cm-l) has been determined for the unirradiated film, irradiated film, benzene extract and Soxhlet extract(Table 3). 

The irradiated film shows an absorption band in IR spectrum (KBr pellet) at 1635 cm T The increase in intensity of this absorption with time is a measure of the conversion rate. Parallel to this the solubility/swelling of the film in THF or toluene should be qualitatively determined. 

Table III lists the contribution to the overall irradiated film solubility rate from the enhanced solvent penetration resulting from radiation exposure. The values for Sr(IF) and Sr(IP) in Table III were calculated using the equations shown in Figure 2. The % contribution to the overall solubility rate, 100 [Sr(IF)—Sr(IP)]/Sr(IF), shown in Table III increased as the radiation dose increased. This behavior is expected since the number and possibly the size of the voids created in the film would be expected to increase as the radiation dose increased.

Photon sensitivities are measured relative to PMMA and were obtained by imaging a 1mm wide slit, illuminated by a 1000 watt Hg lamp focused through quartz condenser optics, onto the substrate for varying times. Exposure times were recorded as the time necessary to allow complete removal of the resist in the irradiated areas, with no thinning in the unexposed areas. The irradiated films were developed in methyl isobutyl ketone (MIBK)/2-propanol (7 3 v/v) for the copolymers and terpoly-mers, and MIBK for PMMA. 

Dose reader for irradiated films. (Courtesy of Elektron CrossKnking AB.)... 

A dose reader designed for direct reading from irradiated films... 

Polyethylene. In order to obtain the degree of crosslinking, the irradiated film was extracted with hot xylene, and the sol fraction, S,... 

Infrared analysis (6) of irradiated film showed an increase in the yield of trans-vinylene unsaturation (Figure 2). The calculation from the... 

Gel permeation chromatography on dissolved irradiated and non-irradiated films (THF/water 99V/1V) was performed on a Waters HPLC apparatus equipped with both UV (280 nm) and refractive index detectors and with 4 microstyragel columns (105, 104, 103, 500). THF was used as eluent. The elution time was calibrated with polystyrene standards. The same concentrations were employed for... 

Ultraviolet transmission spectra of irradiated films showed absorbance changes similar in sensitivity to those of yc. The spectrum itself only showed a general absorbance increase in the 220-400 m/x region, with a slight indication of band formation near 315 m/x. Plots of absorbance increases against exposure time were linear for 285 m/x (ketonic carbonyl formation) and 315 m/x, with the absorbance increase amounting to 0.32 and 0.25, respectively, for 20/x films exposed 300 min. 

The C Is spectrum for the non-irradiated film shows an envelope containing significant contributions from CF bonds in agreement with previously reported data (3J5). After irradiation, a decrease in the... 

Figure 1 shows the ultraviolet (UV) spectra of an unexposed MP2400-17 film and a film exposed to 470 mJ/cm. The films were spin coated onto quartz substrates and baked at 90 C for 30 minutes in a forced-air oven. The film thickness after baking was 0.465 bm. Exposure was accomplished by direct irradiation of the film to the narrowed output of a Math Sciences EXL-100 KrF excimer laser. Thirty pulses were delivered at an average dose of 15.7 mj/cm per pulse. The spectrum of the quartz substrate was automatically subtracted from the spectra of the films on the substrates to obtain Figure 1. The absorbance of the two films is the same at wavelengths below 310 nm and the solid curve in Figure 1 represents the absorbance of both films. The absorbance at 248 nm is 0.49 for both films. Destruction of the PAG by the 248 nm radiation, as evidenced by the disappearance of the longer wavelength absorption in the irradiated film, presumably occurs after nonradiative energy transfer.

Values for M were calculated using the PAG peak areas determined for several irradiated films as shown in Table I. The area of the PAG peak in each chromatogram was normalized to the area of the internal standard benzene peak and corrected by subtracting the normalized area of the background peak that was determined from the chromatogram of the film exposed to 418 mJ/cm . The PAG concentration M is proportional to the peak area and was normalized by setting the area of the peak for the unexposed film to 1.0. Figure 5 shows a plot of log M versus dose. The solid line is a least-squares fit to the data and G was determined from the slope of this line to be 0.013 (mJ/cm ) . ... 

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