详细研究了准分子激光光束均匀性的各项评价指标,加工窗口描述了加工任务本身对光束均匀度的要求;能量分数回答了具体加工窗口即均匀度要求下的能量利用率问题;平顶因子则描述了整个光斑能量分布范围内的均匀性问题.利用激光波面分析仪对不同均匀器所获得的均匀光束进行评价比较,蝇眼透镜均匀器能量利用率高,整个光斑内的均匀效果好,但最佳均匀截面的位置动态范围小;组合棱镜均匀器均匀截面动态范围大,但整体均匀效量较差.

The evaluating norms of excimer laser beam uniformity are analysed in detail. The process window defines uniformity requirements of the excimer laser,while the energy fraction answers the problem of useful percentage of energy within a giving process window. The top-hat factor defines the uniformity of the whole energy range, and the dynamic range is the variation range of screen-homogeneity in the specific application. The beam uniformity obtained by different beam homogenizer is compared by using CCD laser beam analyzer. With the fly's eye homogenizer, energy untilization ratio is high and the homogeneity of the whole light spot is fine, but the dynamic range of the screen-homogeneity is narrow; The prisms has wide dynamic range but bad homogeneity.