Dynamic absorption coefficients of CAR and non-CAR resists at EUV

Abstract

The dynamic absorption coefficients of several CAR and non-CAR EUV photoresists are measured experimentally using a specifically developed setup in transmission mode at the XIL beamline of the Swiss Light Source. The absorption coefficient α and the Dill parameters ABC were measured with unprecedented accuracy. In general the α of resists match very closely with the theoretical value calculated from elemental densities and absorption coefficients, whereas exceptions are observed. In addition, through the direct measurements of the absorption coefficients and dose-to-clear values, we introduce a new figure of merit called Chemical Sensitivity to account for all the post-absorption chemical reaction ongoing in the resist, which is also predicts a quantitative clearing volume, and respectively clearing radius, due to the photon absorption in the resist. These parameters may help in deeper insight into the underlying mechanisms of EUV concept of clearing volume and clearing radius are then defined and quantitatively calculated.

Metal Sensitizer in Chemically Amplified EUV Resist: a Study of Sensitivity Enhancement and Dissolution

“…As seen in Fig. 7, the reference resist without metal sensitizer has EUV absorption at 6.34 �� �� , slightly higher than previously reported EUV resists [18]. Counterintuitively, as more metal sensitizers are added to resists, absorption decreases surprisingly (Fig.…”

Hybrid EUV Resists with Mixed Organic Shells: A Simple Preparation Method

“…The main consequence is that absorption of light in this energy regime (soft X‐ray) leads to photoionization instead of resonant electronic transitions and, therefore, the chemical reactions are mainly performed by the secondary electrons generated upon irradiation. In addition, the probability of absorption of EUV photons is mainly determined by the elemental composition of the photoresist,, rather than the selection rules of classical photochemistry, where the characteristics of the frontier molecular orbitals can be used to predict the absorption probability.…”

Optimization and sensitivity enhancement of high-resolution molecular resist for EUV lithography

“…For xMT without metal additive the absorption coefficient was measured as 4.3 μm -1 and rose to 8.3 μm -1 with 2 percent metal loading. Experimental details and in depth discussion is reported in [9].…”