Photomask

About: Photomask is a research topic. Over the lifetime, 7917 publications have been published within this topic receiving 54524 citations. The topic is also known as: photoreticle & reticle.

Method of repairing phase shift mask

Abstract: A method of repairing a phase shift mask includes exposing upper and side surfaces of the phase shift pattern of the mask, selectively forming a passivation layer on the surfaces of the exposed phase shift patterns, and then cleaning the phase shift mask on which the passivation layers are formed. The repairing of the phase shift mask is carried out in the midst of a series of photolithographic exposure processes in which the phase shift mask is used to transfer an image to a photoresist layer or layers. After the photomask is cleaned, a determination is made as to whether the transmittance of the phase shift pattern is above a threshold value.

Photomask management method and photomask wash limit generating method

Abstract: A photomask is washed and at least one physical amount of transmittance and phase difference of the photomask, dimension of a pattern, height of the pattern and a sidewall shape of the pattern is measured. After this, the two-dimensional shape of a borderline pattern previously determined for the photomask is measured. Lithography tolerance is derived by performing a lithography simulation for the measured two-dimensional shape by use of the measured physical amount. Then, whether the photomask can be used or not is determined based on the derived lithography tolerance.

Techniques for removal of contamination from EUVL mask without surface damage

Abstract: Mask defectivity is an acknowledged road block for the introduction of EUV lithography (EUVL) for manufacturing. There are significant challenges to extend the conventional methods of cleaning developed for standard 193nm optical photomask to meet the specific requirements for EUV mask structure and materials. In this work, the use of UV activated media for EUV mask surface cleaning is evaluated and the effects on Ru capping layer integrity are compared against conventional cleaning methods. Ru layer surface is analyzed using roughness measurements (AFM) and reflectivity changes (EUV-R and optical).

Attenuated phase-shifting mask with a single-layer absorptive shifter of CrO, CrON, MoSiO, and MoSiON film

Abstract: Attenuated phase-shifting mask with a single-layer absorptive shifter of CrO, CrON, MoSiO or MoSiON films has been developed. The optical parameter of these films can be controlled by the condition of sputtering deposition. These films satisfy the shifter requirements, both the 180-degrees phase shift and the transmittance between 5 and 20% for i-line. MoSiO and MoSiON films also satisfy the requirement for KrF excimer laser light. Conventional mask processes, such as etching, cleaning, defect inspection and defect repair, can be used for the mask fabrication. Defect-free masks for hole layers of 64 M-bit DRAM are obtained. Using this mask, the focus depth of 0.35-micrometers hole is improved from 0.6 micrometers to 1.5 micrometers for i-line lithography. The printing of 0.2-micrometers hole patterns is achieved by the combination of this mask and KrF excimer laser lithography.

Process for producing the passivation layer of an active matrix substrate by back exposure

Abstract: A photoresist 10 is exposed to light from behind a substrate by using as photomask a wiring electrodes 2 and 4 and a switching element 8 which are individually composed of an opaque member, whereby a passivation layer 9 for the switching element 8 is patterned. By virtue of this method, a photomask becomes unnecessary and jogs of the passivation layer 9 can be formed outside the transparent pixel electrode 7. Therefore, an unsatisfactory orientation of a liquid crystal can be made invisible without enlarging the black matrix of a counter substrate. Furthermore, since a passivation layer can be removed in portions not requiring the passivation layer, image-sticking can be reduced and the quality of displayed picture can be greatly improved. The present invention makes it possible to reduce the number of photomasks used for production of an actively addressing substrate and improve the picture quality of a liquid crystal display.