| 摘要 |
The embodiments of the invention relate to a method and apparatus for measuring the etch depth between etching for an alternate phase shift photomask in a semiconductor photomask processing system. The apparatus for measuring the etch depth of a substrate (520) in an etch processing system comprises a measurement cell (550) coupled to a mainframe of the etch processing system, and an etch depth measurement tool (460) coupled to the bottom of the measurement cell, wherein an opening (560) at the bottom of the measurement cell allows light beams to pass between the etch depth measurement tool and the substrate. The embodiments of the invention also relate to the method of preparing an alternate phase shift mask by partially etching the quartz substrate to an initial etch depth, followed by measuring the etch depth with an integrated measurement tool. The substrate is then etched and measured repeatedly until the targeted etch depth has been reached. |
