Patent ID: 9524362
Filing Date: 2016-12-20
CPC Classification: G03F,G06F

Claim Text:
1. A method of decomposing pattern layout for generating patterns on photomasks, comprising: transmitting an integrated circuit layout comprising a plurality of first features and a plurality of second features to a computer readable storage medium; classifying the first features into a first feature pattern and a second feature pattern; classifying the second features into a third feature pattern and a fourth feature pattern so that the second features in the third feature pattern overlap the first features in the first feature pattern, and the second features in the fourth feature pattern overlap first features in the second feature pattern; checking pitches of the second features to determine whether the pitches are less than a minimum exposure limit; classifying portions of second features in the fourth feature pattern into a fifth feature pattern and a sixth feature pattern when the pitches of the second features in the fourth feature pattern are less than a minimum exposure limit; and outputting the first feature pattern to a first photomask, the second feature pattern to a second photomask, the third and fifth feature patterns to a third photomask, and the fourth and sixth feature patterns to a fourth photomask.