Method for designing phase-shifting masks with automatization capability

A method for designing a phase-shifting mask from design data, the method comprising the steps of:

• measuring a shortest distance between shapes of the clear areas, in the design data;
• defining a pair of the shapes to be adjacent when the shortest distance therebetween is less than a predetermined threshold, and then storing the defined pairs of shapes;
• classifying all shapes of the clear areas into groups based on the above adjacent relationship;
• expressing the adjacent relationship in the form of a simplified line-segment-and-node graph and observing whether or not there exists an odd-numbered loop therein for each group;
• and, for the group whose expressing graph contains at lest one odd-numbered loop,
• arranging the phase shifters, by utilizing phases of 0.degree., 180.degree. and an integral multiple of 360.degree./m (where m is a positive integer starting from three onward), in a manner to satisfy the following conditions:
• a first condition where the phase differs in between any pair of given shapes neighboring at a distance less than the threshold, and
• a second condition where minimum becomes a total sum of length of shape sides facing at the distance less than the threshold and at a phase difference therebetween being other than 180.degree.,
• wherein, for the group whose expressing graph contains no odd-numbered loop, the method comprises the step of:
• arranging the phase shifter on one of the adjacent shapes so that mutually neighboring clear areas within the threshold have an opposite phase to each other.

A method for designing a phase-shifting mask, the method comprising the steps of:

• arranging a phase shifter so that a phase difference between neighboring clear areas is set to approximately 180.degree.;
• setting to approximately 180.degree. a relative phase of opening areas enclosed by a pair of the clear areas defined in the above step, when the opening areas enclosed by the pair of clear areas is parallel to the pair of clear areas, and the number of opening areas enclosed by the pair of clear areas are even numbered in a cross sectional area vertical to the pair of clear areas;
• setting to approximately 180.degree. the relative phase between the pair of opening areas and the enclosed opening areas;
• assigning approximately 180.degree. for a relative phase of the enclosed opening areas when the number thereof is odd numbered;
• and
• setting to approximately 180.degree. or approximately 90.degree. the relative phase between the pair of clear areas and the enclosed opening areas after completing the previous steps.

A method for designing a phase-shifting mask, the method comprising the steps of:

• extracting a first pattern group of clear area where a decimal part lies between 0.44 and 0.55, the decimal part is of a quotient obtained from dividing an amour of phase difference by 180.degree.;
• supplying a first shape data expressed by all patterns included in the first pattern group;
• extracting a second pattern group of clear area where the decimal part is less than 0.94, the decimal part is of a quotient obtained from dividing the amount of phase difference by 180.degree.;
• and
• supplying a second shape data expressed by all patterns included in the second pattern group.