Direct temperature metrology helps minimize CA-resist CD variation

FEB temperature is critical during the processing of chemically amplified 2 48nm land below) photoresists. Variations in temperature directly affect CD s of final resist patterns. Many other process parameters can also influenc e CDs, however. Work with an instrumented wafer for direct, precise tempera ture measurement and mapping of wafer temperature over time during a FEB cy cle has helped separate out CD variations caused by FEB temperature from th ose due to other factors. This has allowed improvement in the control of FE B hotplate temperature, virtually eliminating FEB temperature variation as a significant cause of CD variability.