| 摘要 |
<p>PURPOSE:To make it possible to obtain fine and bright patterns by cofining the RMS (root mean square) value of wave front aberrations to a specific value or below after power component correction. CONSTITUTION:The RMS value (after the power component correction) of the wave front aberration expresses only the component to directly affect optical performance and, therefore, the surer assurance of the optical performance is possible. Namely, the RMS (root mean square) value is calculated by using all measurement points and, therefore, its information quantity is large and is hardly affected by measurement errors. Statistical processing is possible as well. The RMS value of the wave front aberrations after the power component correction is, thereupon, used and is so adjusted that this value attains <=0.015. This upper limit is simulated by taking the various aberrations to be generated by the influence of the respective components of a refractive index analysis excluding the power components into consideration and is determined as the value at which the performance of a projecting lens is exhibited. Aberrations are increased and the member is no longer adequate as a member for photolithography if the RMS value is >=0.015.</p> |
