| 摘要 |
An apparatus for measuring internal stress of a membrane formed in a reticle, including a temperature adjustment device configured to change a temperature of the membrane from a first temperature to a second temperature; a resonance frequency finding device configured to find a first resonance frequency of the membrane at the first temperature and a second resonance frequency of the membrane at the second temperature; and a stress calculating device configured to calculate the internal stress based on the first and second resonance frequencies. |
