Table 1. Properties of the Pure and Dyed PS Films Studied Herein.

			temperature at which				exposure threshold per pulse
film	starting solutiona (wt % PS)	film thicknessb (nm)	hole expandscT1 (°C)	film disappears T2 (°C)	transmittance 532 nm T	absorbance 532 nm A = 1 – T – R	single pulse (mJ/cm2)	0.5 s of pulsesd (mJ/cm2)
(a) Exposure: Pulsed Laser; Film: Spun on, Dyed; MW PS: 400 000 (Films 1–4), 45 000 (Film 5)
1	0.25	85 (20)	55 (100)	65 (110)	0.44	0.45	10.5	3.3
2	0.75	105 (30)	65 (100)	75 (110)	0.36	0.55	28.1	7.4
3	1.25	125 (55)	95 (110)	105 (120)	0.27	0.66	66.7	15.5
4	1.75	200	110	120	0.18	0.77
5	0.75	100	45	50	0.37	0.55	11.6	9.7/5.6
(b) Exposure: CW Laser; Film: Doctor Blade, Gradient Thickness, Dyed; MW PS: 400 000
6	1.25	80	120	125	0.52	0.37	2.6 × 106
		120			0.49	0.40
		170			0.40	0.50
(c) calculatede optical properties for pure PS
		thickness (nm)			transmittance 193 nm	absorbance 193 nm
		30			0.16	0.63
		55			0.04	0.82
		80			0.01	0.84
		>120			<10–3	0.846

^aFor dyed films 1–6, the starting solutions all have 1.25 wt % SR7B.

^bValues in parentheses (in this column and the following two) are for spin-coated films made without dye.

^cFor dyed films, the temperature at which holes first begin to expand. For films without dye, the temperature at which holes first become visible.

^dFor films 1–4, the pulse rate is 6 kHz. For film 5, the two listed thresholds are for 6 and 55 kHz, respectively.

^eUsing Fresnel equations²⁴ at normal incidence with a complex dielectric constant²² of 1.752 – i3.504 at 193 nm.