Advanced on-tool wafer temperature sensors and integration

The needs for measuring the temperatures of wafers, photomasks or tool hardware under semiconductor process conditions are gaining attentions from both fabs and OEMs in recent years. For wafers and photomasks, the thermal environments during process directly control the reaction rates and reaction equilibrium of the process. For processing tools, any change in temperature within or nearby the process areas can have direct consequences on the device performance and yield rates. [1, 2] To highlight the critical roles that temperature play in modern semiconductor processing, consider the effect of a 3 degree Celsius temperature variation on a 12-inch wafer in the 10 nm node. The change in linear dimension due to such a temperature variation, is approximately 12 in × 25.4 mm/in × 10E-6 × 3, or ~914 nm. This is over 90 times the transistor length scale over the entire 12 inch wafer. Even if such temperature variation is limited to within a single 5mm × 5mm device area, the resulting shift in dimension is still on the order of 15 nm, significantly greater than the critical feature size that the technology node requires. In an era where multiple-patterning is becoming the standard practice, controlling such temperature-related alignment budget loss is critical.