Direct temperature metrology helps minimize CA-resist CD variation

摘要

PEB temperature is critical during the processing of chemically amplified 248nm (and below) photoresists. Variations in temperature directly affect CDs of final res st patterns. Many other process parameters can also influence CDs, however. Work with an instrumented wafer for direct, precise temperature measurement and mapping of wafer temperature over time during a PEB cycle has helped separate out CD variations caused by PEB temperature from those due to other factors. This has allowed improvement in the control of PEB hotplate temperature, virtually eliminating PEB temperature variation as a significant cause of CD variability.