ASML stepper and scanner metrology can be used to monitor wafer substrate, deposited film, and bonded wafer thicknesses on each wafer aligned and exposed.

Wafer and Resist thickness measurement monitor using ASML 5500 Level Sensor metrology

Many Semiconductor wafer fabs processing advanced compound semiconductor, MEMS, and LED type devices are using substrates with large variations in thickness. ASML stepper and scanner metrology can be used to monitor wafer substrate, deposited film, and bonded wafer thicknesses on each wafer aligned and exposed. The leveling system is sensitive enough to detect even photoresist thickness changes. As a result, this system can be used to SPC monitor incoming substrate thicknesses, CMP processes, thin film deposition, and liquid spun-on coating processes. This is extremely important to ensure the process is in control, and that there are no equipment or yield failures due to the substrate or film thicknesses exceeding the leveling operating range.

 

Correlation Curve used to monitor substrate thickness (Source from HP)

 

Correlation Curve used to monitor nominal photoresist thickness (Source from HP)

 

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