光刻机曝光均匀性在线检测方法

On-Line Monitoring Methods for the Exposure Uniformity of the Stepper

光刻机的曝光量和焦距会随着做片量的增加发生漂移,具体表现为曝光场内和圆片内出现曝光不均的质量异常。设计了针形解析图形和方形显开解析图形,利用Ultra Step 1000光刻机进行实验,分析了曝光量和焦距的变化对解析图形解析值的影响。结果表明,曝光量对针形光胶解析图形影响较大,焦距对方形显开解析图形的影响较大。设计了解析图形在曝光场内和圆片内的布局方案,以及在线检测曝光场内和圆片内的曝光均匀性的具体方法,利用该方法可以有效提高光刻机曝光均匀性的在线监控效率,提早预防曝光不均异常现象的发生。该监控方法可以应用于其他类型的光刻机。

The exposure dose and focus will change as a stepper runs continuously, as a result, nonuniform exposure will appear both within the field and wafer. Based on the designed pin and the clear square resolutions, experiments were conducted on Ultra Step 1000 to analyze the influence on the resolution under different exposure doses and focus. And it is concluded that the exposure dose has a prominent effect on the pin, and focus has a prominent effect on the clear square. Layouts of resolution marks within the field and wafer, as well as on-line monitoring methods of the uniformity within the field and wafer were designed to effectively improve the on-line monitoring efficiency of exposure uniformity and to prevent the unevenness of exposure in advance. The monitoring methods can be applied to other types of steppers.