| 摘要 |
The present invention relates to a method of determining a thickness of at least one layer on at least one semiconductor wafer (12), comprising the steps of: projecting a first laser pulse (14) on a surface (16) of the at least one layer (10), thereby generating an acoustical wave due to heating of the surface of the at least one layer (10); after a propagation time of the acoustical wave, projecting a series of second laser pulses (18) on the surface (16) of the at least one layer (10); measuring reflected laser pulses (20) of the second laser pulses (18), thereby sensing the times of reflection property changes of the surface (16) of the at least one layer (10); and determining the thickness of the at least one layer (10) by analyzing the times of reflection property changes. The present invention further relates to a system for determining a thickness of a layer (10) on a semiconductor wafer (12).
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