Press-patterning of polymers to yield optical structures is being pursued in optics and photonics to yield low-cost optical components. This is a promising technology for the low-cost and high-throughput fabrication of polymeric photonic components. The processing of such imprinted photonic components is usually done using a metallic shim where a pattern is generated on the shim by electroforming or electroplating. The shims are then used to replicate patterns on plastics and polymers under high temperatures and pressures. Under the correct conditions, the polymer flows and replicates a diffraction grating.Polymeric diffraction gratings and holograms have applications in a multitude of photonic applications for diffractive optics. This requires materials that are transparent in the visible region, and preferably have relatively high refractive indices in order to achieve a high diffraction efficiency. In addition, in order to facilitate processing by the press-patterning method that will be further described in this paper, polymeric materials that are amenable to spin-coating and show good thermoplastic behavior are also desired.Optically transparent, high-refractive index polyimides were tested for their ability to be processed and patterned using a press-patterning method. A process that allowed the materials to be patterned were developed, and measurements were taken to validate the results. Our initial results showed successful press-patterned polyimide films with grating structures having submicron line and trench widths and step heights of less than 0.5 microns.

This paper presents our progress in developing spin-on, thermosetting hardmasks and bottom antireflective coatings (BARCs) for 193-nm trilayer usage. Binder materials that were used in preparing the silicon-containing hardmasks include polymers with pendant alkylsilane function and various polyhedral oligomeric silsesquioxane (POSS) substances, with the hardmasks being very transparent at both 193 and 248 nm. The second generation hardmasks (POSS-containing) offer significant improvements over earlier materials in oxygen (O2) plasma etching resistance. The etching selectivity (O2 plasma) for a trilayer BARC relative to the best-case hardmask is about 31.5:1 (15-second etch), with the selectivity numbers being much higher for longer etching times. The preferred hardmask is both spin-bowl and solution compatible. The new trilayer BARCs use binders that are rich in aromatic content for halogen plasma etching resistance, but the antireflective products also feature optical parameters that allow low reflectivity into the photoresist. The BARCs are very spin-bowl compatible. At about 500-nm film thickness, selected BARCs have provided 80-95% planarity over 200-nm topography. Combining the two thermosetting products (hardmask and BARC) with a thin 193-nm photoresist in a trilayer configuration has given excellent 80-nm L/S (1:1) after exposure and wet-development. A conventional resist has provided 100-nm L/S (1:1.4).

This paper highlights the performance of new materials that have been developed for use in 193-nm trilayer microlithography. The products are embedded etch masking layers (EMLs) and bottom antireflective coatings (BARCs). Both coatings are spin applied from organic solvent(s) and then thermoset during a hot plate bake. The EMLs (middle layers) are imaging compatible with JSF, Sumitomo, and TOK 193-nm photoresists. Best-case trilayer film stacks have given 100-nm dense and semi-dense L/S. Plasma etching. selectivities and solution compatibility performance of the EMLs meet or exceed proposed product targets. In addition, the EMLs exhibit both solution and plasma etching properties that should lead to successful rework processes for photoresists. The multilayer BARCs offer good thick film coating quality and contribute to excellent images when used in trilayer applications. Combining the EMLs, which are nearly optically transparent (k = 0.04) at 193-nm, with the new trilayer BARCs results in outstanding Prolith simulated reflectance control. In one modeling example, reflectance is a flat line at 0.5% on five different substrates for BARC thicknesses between 300 and 700-nm.