Progress Towards Production Worthy EUV Photoresists: Balancing Litho, Outgassing and OOB Performance

Abstract

Implementation of EUV Lithography (EUVL) for device high volume manufacturing (HVM) requires advanced photoresists capable of meeting the criteria of advanced logic and memory design rules. To achieve the level of performance required, resists must show excellent performance in terms of resolution, LWR (or CDU) and sensitivity. In addition, resists must meet the outgassing criteria required for HVM on the NXE toolset. Lastly, it is anticipated that resists with low OOB sensitivity will also be required.In this paper, we describe our progress in all of these areas. Based on our results, we believe we are on track to deliver production worthy resists for the EUVL era.

Driving Force Dependence of Electron Transfer from Electronically Excited [Ir(COD)(μ-Me2pz)]2 to Photo-Acid Generators

“…Note that the excitation spectra that give rise to both emission features (λ em = 575 and 705 nm) are virtually identical, confirming that both are attributable to a single molecular species. The 575 nm emission has been assigned to 1 20 Cyclic voltammetry of [Ir(COD)(μ-Me 2 pz)] 2 in CH 3 CN solution has been reported previously. 21 One-electron oxidation occurs at 0.28 V, and the first one-electron reduction is at −2.51 V vs SCE (saturated calomel electrode).…”

“…The strong acid reacts with acid sensitive functional groups in a polymeric matrix, creating a solubility switch and ultimately producing a lithographic pattern. Such lithographic patterning schemes are important as they are used to manufacture advanced integrated circuits for semiconductor chips. , The onium salt photoacid generators (PAGs, Figure ) used in photolithography have been the subject of much research owing to the ability to tune their properties to the different wavelengths typically used in modern optical lithography (248 and 193 nm). Extreme ultraviolet (EUV) lithography at 13.5 nm has been identified as a leading candidate for next-generation high-resolution patterning technology …”

“…TBTPS-PFBUS (1): Tris(4-(tert-butyl)phenyl)sulfonium bromide (5.00 g, 9.77 mmol, 1.0 equiv) and potassium perfluorobutanesulfonate (3.64 g, 10.8 mmol, 1.1 equiv) were dissolved in dichloromethane (100 mL) and water (100 mL) and vigorously stirred at room temperature for 18 h. The layers were separated, and the organic phase was washed with water (5 × 50 mL, 250 mL total) and concentrated under reduced pressure to afford the title compound (6.71 g, 85%) as a white solid. 1 H NMR (500 MHz, (CD 3 ) 2 CO) δ: 7.84−7.88 (m, 12H), 1.35 (s, 27H). 13 Photochemistry.…”

Recent EUV Resists toward High Volume Manufacturing

“…A dissolution rate study of this class of resists varying the leaving group design was conducted by Ongayi et al It indicated that lower Ea, hydrophilicity, and larger size of leaving group lead higher sensitivity, however, hydrophobicity seemed required to some extent for the better resolution in order to prevent pattern collapse from capillary force between lines [23]. In another study by [26]. Recently, a novel concept to enhance EUV resist sensitivity, photosensitized chemically amplified resist (PS-CAR) has been brought by Tagawa et al [27].…”