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.

Mask for stepper

Abstract: PURPOSE:To provide the mask for stepping which easily realizes inclined illumination by using the existing device as it is. CONSTITUTION:This mask 16 to be used for the stepper for fine patterns is constituted by disposing, for example, phase type gratings 14, as an optical element having a function to incline light I for irradiation according to the numerical aperture of a projection lens on the light source side of the pattern surface of a mask substrate 11 and integrating these gratings 14 and the mask substrate 11. The simultaneous mounting as well as attaching and detaching of the gratings 14 an the mask substrate 11 are possible in this way and the imaging at the highest resolution of the projection lens is possible without modifying the existing stepper. In addition, the resolution equiv. to the resolution of the phase shift mask method by the conventional system is attained with arbitrary patterns even if the phase shift mask is not used.

Eaves quantity measuring method for phase shift mask

Abstract: PROBLEM TO BE SOLVED: To correctly grasp the eaves quantity of a phase shift mask without making a sectional observation of the phase shift mask and to guarantee the quality of the phase shift mask more securely. SOLUTION: The method of measuring the eaves quantity of a circuit pattern 10 of an eaves type Levenson PSM 100 includes a stage of forming the circuit pattern 10 and a monitor pattern 20 of specified size on quartz-made blanks 1, a stage of forming step part 33A and 33B on the blanks 1 where the monitor pattern 20 and circuit pattern 10 are formed by performing anisotropic dry etching and isotropic wet etching, and a stage of removing the monitor pattern 20 from the blanks 1 where the step parts 33A and 33B are formed and measuring the size of a specified area 25 demarcated with the step part 33B right below the monitor pattern 20 as the eaves quantity. COPYRIGHT: (C)2004,JPO

Impact of mask topography and resist effects on optical proximity correction in advanced alternating phase-shift process

Abstract: This paper develops and validates a methodology for rigorously modeling the pattern transfer in alternating Phase Shift Mask (altPSM) process by incorporating mask structure, partially coherent illumination, polarization and resist in a full-vector electromagnetic (EM) model. Mask topography is included in EM simulation to solve for the field immediately after the mask. To model the partially coherent illumination, the light source is decomposed into a set of plane waves with different angles of incidence on mask. Each wave requires an EMF simulation over the mask. A perturbation approach is developed in this paper to reduce the EM simulation time by over 50%, thus enabling the vector model of partial coherence. Then the field after mask is decomposed into TE and TM polarized waves so as to calculate the field in resist/BARC/silicon multilayer. At high NA, this full vector model is needed to investigate altPSM because there exists appreciable difference between the images due to TE and TM waves. TM wave degrades more severely in resist, thus TE is more desirable. The experiments were conducted at Tokyo Electron Texas LLC. on a 248nm KrF stepper, NA 0.6, σ 0.3. Both experiments and simulations show that transmission imbalance depends on defocus. When the focal plane is moved towards the lens, the 180° space can be brighter than 0°.The 0° space is more sensitive to defocus and has larger CD variation than 180° does. Finally the simulated patterns are compared with experimental SEM picture.

Mask for exposure and its production and production of semiconductor device

Abstract: PURPOSE: To provide a halftone type phase shift mask which is formed within a permissible range of a phase difference and transmittance by distinctly defining this permissible range CONSTITUTION: This halftone type phase shift mask has translucent patterns of the reference transmittance T formed out of a film which is translucent and has the phase difference to light passing a light transmissible substrate on this light transmissible substrate The range of the phase difference and the transmittance where a relative depth of focus of >=90% is obtainable at an exposing wavelength of 365nm is indicated on a plane defining the transmittance of the translucent film patterns and the phase difference to the light transmissible substrate at X- and Y-axes A square shape inscribing the range of the phase difference and transmittance indicated on this plane is regulated by the coordinates at its vertex The phase difference and transmittance of the translucent film patterns are so set as to attain the values within this square shape