ArF quarter-micron projection lithography with an aspherical lens system

Na3Ba2(B3O6)2F: Next Generation of Deep-Ultraviolet Birefringent Materials

“…Birefringent materials, which can modulate the polarization of light, are very important and interesting in optical communication and the laser industry as they are vital crystalline materials in producing optical devices such as polarization beam splitters, optical isolators, circulators, and Q switches. − After continuous efforts in the past few decades, many birefringent materials have been found. − YVO 4 , TiO 2 , LiNbO 3 , and CaCO 3 are the most advanced birefringent materials, which have been widely used in the near-infrared (NIR) and visible range. Meanwhile, with the rapid development of ultraviolet (UV) technology for communication and sensing systems, birefringent crystals in the deep UV (λ < 200 nm) range are of current interest and are attracting considerable attention owing to the higher power density, higher capacity, faster data transmission rate, and superior anti-interception and anti-interference ability of UV technology.…”

Challenges in excimer laser lithography for 256M DRAM and beyond

“…Pre-baking for 90sec a t 90°C was performed. Exposure was done by in-house A r F excimer laser stepper (N.A 0.45) (7). After exposure, post exposure baking (PEB) for 90sec a t 95'C was done.…”

An Anti‐Reflection Coating for Use with PMMA at 193 nm

“…In order to design an ARC, we must know the complex indexes of refraction of PMMA, the ARC, and the substrate at 193 nm. The complex index of refraction is given by the expression N = n + ik [1] where n accounts for the change in wavelength in a material, and k accounts for attenuation. Complex indexes of refraction of many substances, including Si, SIO2, and many metals, have been measured from x-ray to infrared wavelengths using a variety of techniques, such as refiectivity, transmissivity, and eUipsometry.…”

“…Despite its relatively low sensitivity and poor plasmaetch resistance, poly(methyl methacrylate) (PMMA) continues to be used as a resist for ArF excimer laser lithography (193 nm) due to its high transparency and high inherent resolution (1). Gratings with periods of 100nm (nominal linewidth 50 nm) have been recorded in PMMA using achromatic holographic lithography at 193 nm (2,3).…”