Samsung Electronics Co., Ltd.

Jong-Rak Park

Gi-Sung Yeo

Seong-Woon Choi

Young-Seog Kang

Sung-Hoon Jang

A photomask for use in photolithography has substrate, a main pattern at one side of the substrate, and a transparency-adjusting layer at the other side of the substrate. The transparency-adjusting layer has a characteristic that allows it to change the intensity of the illumination incident on the main pattern during the exposure process accordingly. In manufacturing the photomask, a first exposure process is carried out on a wafer using just the substrate and main pattern. The critical dimensions of elements of the pattern formed on the wafer as a result of the first exposure process are measured. Differences between these critical dimensions and a reference critical dimension are then used in designing a layout of the transparency-adjusting layer in which the characteristic of the layer is varied to compensate for such differences.

Photomask having a transparency-adjusting layer, method of manufacturing the photomask, and exposure method using the photomask

A method of designing a phase grating pattern and a method of manufacturing a photo mask using the design method are aimed at enhancing the resolution of a photolithographic process. A modified form of illumination, which will irradiate a main mask pattern to be transcribed onto a wafer using the photolithographic process and thereby enhance the transcription process, is selected. An area over which patterns for providing the modified form of illumination is divided into a plurality of subcells. Phase values are arbitrarily assigned and a phase values to the subcells. One of the subcells is randomly selected, and a phase value is assigned to the randomly selected subcell. These steps are repeated producing new arrangements of the phase values assigned to the subcells. The arrangements of the phase values are evaluated to determine whether any of them correspond to the selected modified illumination. When such a correspondence is realized, a phase grating pattern made according to the arrangement of phase values is produced as part of an auxiliary mask or as part of the main mask.

Method of designing phase grating pattern for use in modifying illumination in an exposure process, and method of manufacturing a photo mask system having the phase grating pattern

A method of designing a phase grating pattern provides a modified form of illumination for a main mask, optimum for producing one or more target patterns on a wafer in a photolithographic process. Once the target pattern(s) to be formed on the wafer are decided, an area to be occupied by at least a portion of the phase grating is divided into a plurality of subcells, initial phase values are assigned to each of the subcells, and one of the subcells is randomly selected and the phase value last assigned thereto is changed, and the process is repeated. The process is in an iteration that changes the arrangement of the phase values assigned to the subcells until they converge on one which will provide the design for a phase grating which will produce a modified form of illumination optimum for use in forming the target pattern(s) on the wafer.

Method of designing phase grating pattern providing modified illumination optimum for producing a target pattern and method of manufacturing a photo mask system comprising the phase grating pattern

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Cheongju, South Korea

Jong-Rak Park