Phase-shift mask

About: Phase-shift mask is a research topic. Over the lifetime, 2088 publications have been published within this topic receiving 18058 citations.

Target for forming film and method for manufacturing phase shift mask blank

Abstract: PROBLEM TO BE SOLVED: To provide a target for forming a film for manufacturing a halftone phase shift mask and its blank which can respond to shorter wavelengths of exposure light and have excellent chemical resistance, and to provide a method for manufacturing the halftone phase shift mask blank. SOLUTION: The target for forming a film is used to manufacture a halftone phase shift mask blank which has a single-layer or multilayer semitransparent film having a controlled phase and transmittance on a transparent substrate and simultaneously contains a Si element, Mo element and Zr element as structural elements of at least one layer of the semitransparent film, and the target contains at least two elements of Mo and Zr, with 0.05 to 5 molar ratio of the content ratio (Zr/Mo). A halftone phase shift mask and its blank which can respond to shorter wavelengths of exposure light and have excellent chemical resistance and patterning accuracy can be easily obtained by the present invention. COPYRIGHT: (C)2006,JPO&NCIPI

Apparatus and system for improving phase shift mask imaging performance and associated methods

Abstract: A method for improving the imaging performance in a photolithographic system having a pupil plane and using a phase shift mask. A portion of the pupil plane where a phase error portion of a light from the phase shift mask is located. An aperture is placed at the located portion of the pupil plane. Typically, the phase error portion of the light from the phase shift mask is a zero order portion of the light often referred to as “zero order leakage”. Blocking the zero order leakage significantly mitigates the variations in the intensity of the light that exposes photoresist that is above or below the nominal focal plane. This, in turn, reduces the variations in the linewidths formed on the wafer.

Method for inspecting phase shift mask and inspecting device used for the method

Abstract: PURPOSE:To provide a method and device for exactly obtaining a phase shift quantity and light transmittance by phase shifter parts of a phase shift mask. CONSTITUTION:A Mach-Zehnder interferometer of a sharing system is built by using optical members for UV rays (4a to 4f, 15, 16, etc.). The phase shift quantity and light transmittance by the phase shifter parts 3 are measured directly and nondestructively from the interference light intensity signals obtd. by using the light having the same wavelength as the wavelength of the light used in photolithography and by interfering the light beams past the phase shifter parts 3 and light transparent parts 1b.

System and method for quantifying errors in an alternating phase shift mask

Abstract: A method and system for detecting the quality of an alternating phase shift mask having a number of 180-degree phase shift areas alternating with a number of 0-degree phase shift areas is disclosed. In operation, a light source which provides wavelength-adjustable incident lights illuminates the incident lights on the alternating phase shift mask. The light outputs from boundaries between the 0-degree phase shift areas and the 180-degree phase shift areas of the alternating phase shift mask are detected. Relation curves of the wavelength of the incident light and a light intensity of the boundaries are then calculated. Phase errors of the alternating phase shift mask can thus be measured from the relation curves.

Modeling high-efficiency extreme ultraviolet etched multilayer phase-shift masks

Abstract: Achieving high-throughput extreme ultraviolet (EUV) patterning remains a major challenge due to low source power; phase-shift masks can help solve this challenge for dense features near the resolution limit by creating brighter images than traditional absorber masks when illuminated with the same source power. We explore applications of etched multilayer phase-shift masks for EUV lithography, both in the current-generation 0.33 NA and next-generation 0.55 NA systems. We derive analytic formulas for the thin-mask throughput gains, which are 2.42× for lines and spaces and 5.86× for contacts compared with an absorber mask with dipole and quadrupole illumination, respectively. Using rigorous finite-difference time-domain simulations, we quantify variations in these gains by pitch and orientation, finding 87% to 113% of the thin-mask value for lines and spaces and a 91% to 99% for contacts. We introduce an edge placement error metric, which accounts for CD errors, relative feature motion, and telecentricity errors, and use this metric both to optimize mask designs for individual features and to explore which features can be printed on the same mask. Furthermore, we find that although partial coherence shrinks the process window, at an achievable sigma of 0.2 we obtain a depth of focus of 340 nm and an exposure latitude of 39.2%, suggesting that partial coherence will not limit the feasibility of this technology. Finally, we show that many problems such as sensitivity to etch uniformity can be greatly mitigated using a central obscuration in the imaging pupil.