| 摘要 |
PURPOSE:To minimize an error at the time of changing a unit from a unit of mil to a unit of mum without increasing the size of a chip by setting the chip sizes of two sides of the outer sides of a rectangular semiconductor device defined on a photomask. CONSTITUTION:When a size unit mil represented in an inch system is converted to the unit of mum in a meter system, a rounding error is generated. For example, in a 4-chip reticule, the photomask is formed by a semiconductor device area 1, a scribe line area 2, and a light shielding body area 3. Assuming the size of a horizontal direction in a rectangle forming the chip as X and that of a vertical direction as Y, relation X=x+a/2, and Y=y+a/2 can be established. In such a case, a coefficient 25.4 exists when the sizes X and Y are converted from the unit of mil of the inch system to the unit of mum of the meter system. Therefore, by setting the sizes X and Y at 5mil unit, a decimal place is eliminated and it goes to an integer, therefore, the rounding error can be reduced. |
