Hydrogen SilsesQuioxane, a high-resolution negative tone e-beam resist, investigated for its applicability in photon-based lithographies

Hydrogen SilsesQuioxane (HSQ) has previously been shown to behave as a high-resolution negative tone inorganic e-beam resist, giving single lines less than 10 nm wide. In this work, HSQ has been investigated for its applicability in photon-based lithographies. No measurable sensitivity has been observed for wavelengths of 800-400, 365, 248 and 193 nm. For 157 nm wavelength, negative tone behaviour starts at 650 mJ/cm(2) and for 13.5 nm (EUV) at 50 mJ/cm(2). For 1.3 nm wavelength (X-ray lithography), the negative tone behaviour starts from around 400 mJ/cm(2), indicating that HSQ is 2.5 times more sensitive than positive tone PMMA. Although there is considerable side wall roughness due to the low mask contrast and the low contrast of HSQ, details have been resolved in X-ray lithography down to 50 ran. (C) 2002 Elsevier Science B.V. All rights reserved.