Kabushiki Kaisha Toshiba

Katsuyoshi Kodera

Chikaaki Kodama

Yasunobu Kai

According to one embodiment, a design layout highly likely to be a dangerous point in a lithography process is set, a coherence map kernel for generating the mask layout is set with respect to the set design layout, the coherence map is created based on the set coherence map kernel and the set design layout, the auxiliary pattern is extracted from the created coherence map and shaped to generate the mask layout, a cost function COST for evaluating an optimization degree of the mask layout is defined, the generated mask layout is evaluated using the cost function, and at least one of parameters of the coherence map kernel and parameters in extracting and shaping the auxiliary pattern from the coherence map are changed until the mask layout evaluated using the cost function is optimized.

Mask-layout creating method, apparatus therefor, and computer program product

According to one embodiment, a method is disclosed for determining position of an auxiliary pattern on a photomask. The method can include generating a first set for each of three or more imaging positions of an exposure optical system. The method can include generating a second set for each of the three or more imaging positions by inverse Fourier transforming each of the first set. The method can include calculating a second order differential with respect to the imaging position of an index indicating amplitude of light belonging to the second set. In addition, the method can include extracting a position where the second order differential assumes an extremal value on an imaging plane of the exposure optical system. At least part of positions on the photomask each corresponding to the position assuming the extremal value on the imaging plane is used as a formation position of the auxiliary pattern.

Growing community of inventors

Kanagawa-ken, Japan

Katsuyoshi Kodera