摘要 |
An automated metrology system for photoacoustic measurement of single or multi-layer films, and a method of making the system, are disclosed. Dramatic improvements in the cost of ownership of the system is attained by making the system scalable from a system having a single metrology sub-system for making measurements, to a system having two, vertically stacked metrology sub-systems for making independent measurements. A front end of the system for storing multiple cassettes comprises a robot having vertical travel capable of transferring cassettes to and from each of the first and second metrology sub-systems in the case the system is expanded. The two metrology sub-systems are preferably identical and share much of the optics, a computer as well as the front end of the system. Throughput of the dual system is 1.75-2 times greater than that of a single tool metrology system while the cost is substantially less than two complete single tool metrology systems.
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