| 摘要 |
To measure line width at best focus in a projected circuit pattern, a set pattern is formed on a substrate, and then an array of test patterns formed adjacent the set pattern. The focus varies by predetermined steps along the array, with the focus of a test pattern at an intermediate position along the array corresponding to the focus of the set pattern. By scanning the test patterns and measuring the line width at each test pattern, data can be obtained to provide a curve indicative of focus relative to line width which shows either a maximum or a minimum line width at that focus, dependent on exposure data. This information can be used to change the programming of a stepper for the focus of a projector to obtain focus independent line width and/or to determine the stability of line widths independent of machine focus and/or to determine the stability of line widths independent of the machine focus. |
