Modeling of reactive soluble ARCs and photoresist-ARC interaction

Abstract

The stringent requirements facing modern chemically amplified photoresists and antireflective coatings make computer physical simulation methods a valuable tool for photoresist and ARC research and design. Hypothetical microlithographic processes involving toolsets that are unavailable to the experimenter may be evaluated. Complex photoresist physical reaction phenomena, often difficult to measure experimentally, may be evaluated within the limits of the mathematical models used. This work details the mechanics and application of a custom simulation tool written for the modeled study of reactive soluble ARCs (DBARCs), soluble ARCs, and photoresist-ARC interactionsphenomena not readily modeled by commercially available software at the time of this paper. Photoresist and ARC interactions are modeled by computing two-dimensional composite diffusion and reaction. Soluble ARCs, either reactive (DBARCs) or nonreactive, are modeled using composite diffusion, a full level-set front tracking development method and multiple development rate functions. Physical models, mathematical formulations and numerical methods of solution are shown. Scenarios hypothesizing the origin of photoresist profile foot formation are discussed and modeled. Models of reactive, soluble ARCs (DBARCs) are compared to models of constant development rate soluble ARCs. The effects of specific reactant diffusion and reaction upon DBARC dissolution rate contours are modeled.

Sensitivity of Process Parameters on Pattern Formation of Litho–Cure–Litho–Etch Process

“…where (¼ A½PAGðx; y; z; tÞ þ B) is the optical absorption coefficient, A, B, and C are Dill's parameters, [A] is the acid concentration, and E is energy. After the reflectance and the transmittance of thin film optics are calculated using Berning's theory, 15,17,[20][21][22] two-dimensional (2D) and 3D bulk images of PAG concentration without and with cured patterns are different, as shown in Figs. 2(c) and 2(i).…”

“…For the development model, the rate equations of the resist dissolution are used to map the development rate to the resist latent image. 20,23) The dissolution rate is related to either the instantaneous inhibitor concentration or the relative blocking level. For the enhanced Mack model,…”

Comparative Study of Photosensitive Versus Non-Photosensitive Developer-Soluble Bottom Anti-Reflective Coating Systems

“…The isotropic nature of non-PS DBARC also sets limits on resolution (9). For example, a KrF DBARC can print dense L/S patterns as small as 150 nm, which is limited if compared to an application using a traditional KrF dry etch BARC application.…”

PAG and Quencher Effects on DBARC Performance

“…tapered or curved profile) and poor through-pitch performance, e.g. dense lines are underdeveloped and show footing and isolated lines show undercut due to over development [7][8].…”