Partially Fluorinated, Polyhedral Oligomeric Silsesquioxane-Functionalized (Meth)Acrylate Resists for 193 nm Bilayer Lithography

Abstract

The influence of partial fluorination on the lithographic performance of photoresists based on (meth)acrylate terpolymers containing polyhedral oligomeric silsesquioxane (POSS) pendant groups is investigated in bilayer schemes for 193 nm lithography. For the first time the capability of POSS-functionalized resists for standard lithographic processing, including use of standard developer (0.26 N tetramethylammonium hydroxide) and industrial processing equipment is demonstrated. The optimized resists formulated exhibited high sensitivity (<10 mJ/cm 2 ) and potential for resolution performance comparable to mature 193 nm materials. The role of the fluorinated acid as a component in the terpolymer composition was crucial to the homogeneity of the resist material and its lithographic performance. Also, a photoacid generator (PAG) study revealed that the use of a highly hydrophobic PAG containing organic anion with a long fluorinated chain in the resist formulation improved further the homogeneity of the material and its lithographic performance. The adhesion of the highly fluorinated materials to the substrate is influenced by the type of polymeric underlayer used, whereas best results were obtained on a hard baked novolac polymer.

Photo-patternable fluorinated polyhedral oligomeric silsequioxane-functionalized (POSS-F) polymeric materials with ultra low dielectric constants

“…The first component is the ethyl-substituted POSS methacrylic constituent (MAEPOSS). The influence of POSS substituents on the lithographic characteristics of the resist has been reported previously [25,26]. In addition, it has been shown that silsesquioxane cage groups demonstrate reduced k values because of the decreased material's density, which derives from the way that Si and O atoms are arranged in the silsesquioxane elementary unit [17,27].…”

“…Details on their synthesis are given elsewere [25]. The photoacid generator (PAG), triphenylsulfonium perfluorooctylsulfonate (TPS-PFOS) was obtained from Midori Kagaku.…”

“…1(b)) a novel positive tone resist based on fluorinated, POSS-functionalized terpolymer (POSS-F) was obtained [25]. In Fig.…”

“…t-butyl groups) in the copolymer backbone along with the addition of a suitable photoacid generator in the material can give positive tone lithographic imaging with deep UV exposure. Indeed, it has been shown that partial fluorination has a clear positive effect on both the homogeneity and the lithographic performance of these POSS-functionalized resists in such a way that a new 193 nm resist platform presenting very promising lithographic and etching characteristics and capability for standard lithographic processing has resulted [25].…”

Thermal Behavior of Caged Silsesquioxane (POSS) Studied by Molecular Dynamics Simulations

“…On the basis of the fact that caged type POSSs have internal space and good property of dielectric constants, they have been incorporated into polymer matrices to obtain low dielectric constant materials [14][15][16][17][18][19][20]. In the optoelectronic applications, POSSs have been employed to improve the thermal stability of photo resist [21][22][23][24] and light emitting diode (LED), the response speed of electrochromic materials [25][26][27], and luminescence efficiency.…”