Abstract: The present invention describes a structure and method for reducing or eliminating the flatness distortion effects of a photomask assembly which occurs when a pellicle is mounted to the photomask. The invention is to perform a partial disconnection of the mounting area of the pellicle frame from the print area of the mask. An exemplary embodiment of the present invention achieves the distortion reduction or elimination using a trench in the photomask as the partial disconnection.

Abstract: In a projection apparatus for projecting optical images, an optical mask support stage having a pair of separated arms. Each arm being provided with a respective mask chucking bar that supports a respective edge of a thin glass mask and applies to the respective edge a bending moment away from the center of the mask to reduce or eliminate any gravitational induced sag in the center of the mask thereby improving the quality of the images projected by the apparatus.

Abstract: A monolithic optical pellicle and method of making used to protect a photomask during photolithography processing. The monolithic optical pellicle is comprised of a pellicle plate having a recessed central portion integrally formed with a perimeter frame of the pellicle plate such that it is a one-piece optical pellicle. The monolithic optical pellicle comprises a material of sufficient rigidity to minimize distortions in and maximize durability of the pellicle when used in combination with the recessed portion having a thickness that prevents sagging thereof due to applied forces on the resultant monolithic optical pellicle. This recessed central portion is the optical pellicle portion of the present monolithic optical pellicle, while the integral perimeter frame is used to attach the monolithic optical pellicle at the desired stand-off distance to a photomask. The monolithic optical pellicle preferably comprises a material that is transparent to an exposure field at about 157 nm wavelengths.

Abstract: A reflective mask, useful in extreme ultraviolet lithography (EUVL), and method of formation are disclosed. Instead of patterning an absorbing film stack, as is the case with conventional EUVL masks, the reflective film stack itself is patterned and etched to form a trench in the reflective stack. A hard mask is deposited directly on the reflective substrate. It is patterned and repaired. Then the reflective film is removed in the patterned area to create absorbing trenches. The hard mask may then be stripped or remain in place on the final mask. A liner may be formed on the trench to absorb radiation and protect the sidewalls.

Abstract: A thin transition-metal based scattering layer of a mask blank for use in EPL systems is formed by providing the thin transition-metal scattering layer directly over membrane layers on a lot of substrates, thereby forming a continuous contact between the single transition metal-based scattering layer and the membrane layer. Preferably, the single transition metal-based scattering layer is a single tantalum-silicon composite scattering layer having a stoichiometry of TaxSi. The deposition parameters for depositing the thin transition-metal based scattering layer are adjusted to provide the scattering layer uniformly over all substrates within the lot. A first substrate from the lot of substrates is then selected, an initial stress measurement of the scattering layer is determined and then the substrate is annealed at a first temperature.

Abstract: A thin transition-metal based scattering layer of a mask blank for use in EPL systems is formed by providing the thin transition-metal scattering layer directly over membrane layers on a lot of substrates, thereby forming a continuous contact between the single transition metal-based scattering layer and the membrane layer. Preferably, the single transition metal-based scattering layer is a single tantalum-silicon composite scattering layer having a stoichiometry of TaxSi. The deposition parameters for depositing the thin transition-metal based scattering layer are adjusted to provide the scattering layer uniformly over all substrates within the lot. A first substrate from the lot of substrates is then selected, an initial stress measurement of the scattering layer is determined and then the substrate is annealed at a first temperature.