Reaction mechanism of ZrO _x metal resists with extreme ultraviolet irradiation

Abstract

The reaction mechanism of ZrO-based metal resists by extreme ultraviolet (EUV) exposure was investigated using hard X-ray photoelectron spectroscopy, near edge X-ray absorption fine structure spectroscopy, and X-ray diffraction. EUV exposure did not affect the amorphous structure of the metal resist. After EUV exposure, the π* states of the C atom and the σ* states of the O atom of the cell molecules were reacted. Moreover, EUV exposure decomposed the carbonyl species of the cell molecules and forms the high oxidation states of ZrO x . Thus, the metal resist reaction occurred with the decomposition of cell molecules and the formation of ZrO 2 by EUV exposure.

Highly hydroxylated hafnium clusters are accessible to high resolution EUV photoresists under small energy doses

“…Embedment of a radical acceptor such as methylacrylate (MAA) onto metal clusters or nanoparticles is a current approach to reduce EUV doses. [6][7][8][9][10][11][12][13][14][15][16] A general protocol is depicted in Scheme 1, in which carbon radicals (Rc) attack at a MAA ligand to induce radical chain growth for molecular aggregation. Nevertheless, very few photoresists can reach high resolution patterns with HP <20 nm.…”

Dissolution dynamics of zirconia nanocluster resist

“…The oxygen bridges between tin-oxo cages are generated through dehydration. [4][5][6][7][8] For the zirconia nanocluster resists with methacrylate (methacrylic acid anion) (MAA) ligands, more details have been investigated using hard X-ray photoelectron spectroscopy, 9) near edge X-ray absorption fine structure spectroscopy, 9) X-ray diffraction, 9) time-of-flight secondary ion mass spectrometry with gas cluster ion beam, 10) a mid-IR free electron laser, 11) scanning transmission electron microscopy, 12) simulation, 13,14) electron pulse radiolysis, [15][16][17] and γ-radiolysis with gas chromatography 18) and high performance liquid chromatography. 19) Upon exposure to ionizing radiations, the radical cations of MAA are generated through the direct oxidation by ionizing radiations (ionization) and the oxidation by the oxidizing agents also generated by ionizing radiation (hole transfer).…”

Novel hexameric tin carboxylate clusters as efficient negative-tone EUV photoresists: high resolution with well-defined patterns under low energy doses

“…Inorganic complexes are promising photoresist materials in EUV (extreme ultraviolet) lithography. [1][2][3][4] One obvious advantage is that the EUV absorption efficiencies of metal complexes such as Hf, [5][6][7][8][9][10][11][12] Zr, [13][14][15][16][17][18] Zn, 10,19,20 and Sn [21][22][23][24][25] are 2-3 folds as large as those of polymer-based photoresists. Despite intensive studies, very few inorganic photoresists 3,19 can reach high resolution EUV patterns with half pitches (HPs) <20 nm under low dosage <50 mJ cm −2 .…”