Verification and modification method of rules of do-not-inspect regions, computer program, and apparatus for such verification and modification
A verification method and apparatus for do-not-inspect region rules include storing information specifying do-not-inspect regions, and storing a pixel unit size which defines a length of a single pixel unit. A minimum size verification process includes calculating sizes of do-not-inspect regions, and verifying whether a minimum size rule is obeyed, the minimum size rule requiring that a size of a do-not-inspect region is equal to or greater than a single pixel unit size while referring to the stored pixel unit size. A distance verification process includes calculating distances between pairs of do-not-inspect regions from among the do-not-inspect regions, and verifying whether a distance rule is obeyed, the distance rule requiring that the distance is in a range of greater than zero and less than a predetermined distance.
1. A method of inspecting a defect in a mask used in production of a circuit, the method comprising:
executing by computer hardware implementing processes:
calculating a width and a height of each of a plurality of rectangular shaped do-not-inspect regions of the mask based upon stored information specifying the do-not-inspect regions, and verifying whether a minimum size rule is obeyed, the minimum size rule requiring that the width and the height of a do-not-inspect region be equal to or greater than a width and a height of a single pixel unit;
calculating distances between a pair of the do-not-inspect regions from among the do-not-inspect regions; and
determining that a distance rule is violated when at least one of the distances between the pair of do-not-inspect regions is in a range of greater than zero and less than a determined distance, and modifying the pair of the do-not-inspect regions, the at least one of the distances between which are in the range, so that at least two sides of the pair of the do-not-inspect regions touch each other,
wherein in a case where a longer side of two sides, which face each other, of the pair of the do-not-inspect regions is set to be a first do-not-inspect region, and a shorter side of the two sides of the pair of do-not-inspect regions is set to be a second do-not-inspect region, the second do-not-inspect region is extended such that the shorter side comes in contact with the longer side of the pair of do-not-inspect regions, thereby the pair of the do-not-inspect regions, the at least one of the distances between which are in the range, are modified so that modified sides of the pair of the do-not-inspect regions touch each other.
2. A non-transitory computer-readable medium storing a verification program of do-not-inspect region rules for a mask used in production of a circuit, the verification program causing a computer to execute:
calculating a width and a height of each of a plurality of rectangular shaped do-not-inspect regions of the mask based upon stored information specifying the do-not-inspect regions, and verifying whether a minimum size rule is obeyed, the minimum size rule requiring that the width and the height of a do-not-inspect region be equal to or greater than a width and a height of a single pixel unit;
calculating distances between a pair of the do-not-inspect regions from among the do-not-inspect regions; and
determining that a distance rule is violated when at least one of the distances between the pair of do-not-inspect regions is in a range of greater than zero and less than a determined distance, and modifying the pair of the do-not-inspect regions, the at least one of the distances between which are in the range, so that at least two sides of the pair of the do-not-inspect regions touch each other,
wherein in a case where a longer side of two sides, which face each other, of the pair of the do-not-inspect regions is set to be a first do-not-inspect region, and a shorter side of the two sides of the pair of do-not-inspect regions is set to be a second do-not-inspect region, the second do-not-inspect region is extended such that the shorter side comes in contact with the longer side of the pair of do-not-inspect regions, thereby the pair of the do-not-inspect regions, the at least one of the distances between which are in the range, are modified so that modified sides of the pair of the do-not-inspect regions touch each other.
3. A verification apparatus of do-not-inspect region rules for a mask used in production of a circuit, the verification apparatus comprising:
an information storage storing information specifying a plurality of do-not-inspect regions, and a pixel unit size which defines a length of a single pixel unit;
computer hardware implementing a process(es) that:
calculates a width and a height of each of a plurality of rectangular shaped do-not-inspect regions of the mask based upon the stored information specifying the do-not-inspect regions, and verifies whether a minimum size rule is obeyed, the minimum size rule requiring that the width and the height of a do-not-inspect region be equal to or greater than a width and a height of the single pixel unit size;
calculates distances between a pair of the do-not-inspect regions from among the do-not-inspect regions; and
determines that a distance rule is violated when at least one of the distances between the pair of do-not-inspect regions is in a range of greater than zero and less than a determined distance, and modifies the pair of the do-not-inspect regions, the at least one of the distances between which are in the range, so that at least two sides of the pair of the do-not-inspect regions touch each other,
wherein in a case where a longer side of two sides, which face each other, of the pair of the do-not-inspect regions is set to be a first do-not-inspect region, and a shorter side of the two sides of the pair of do-not-inspect regions is set to be a second do-not-inspect region, the second do-not-inspect region is extended such that the shorter side comes in contact with the longer side of the pair of do-not-inspect regions, thereby the pair of the do-not-inspect regions, the at least one of the distances between which are in the range, are modified so that modified sides of the pair of the do-not-inspect regions touch each other.