The method to measure the imprint temperature variation of resist film with fluorescence probe technique was established. The maximal Rhodamine B concentration was 8 × 10-4 M to achieve higher sensitivity and avoid precipitation problem. The temperature effect was a critical parameter on the temperature sensing, while imprinting pressure was not. The fluorescence intensity of Rhodamine B linearly decayed with time at various temperatures due to the formation of lactone-containing molecule during thermal stressing. The usual imprint time of less than 20 min was not affected by the signal decay effect due to limited percentage of signal variation during 100-200 °C. The technique based on fluorescence probe method was successfully applied to measure the resist temperature variation of the imprint on the resist film of 6-in. wafer.
- Imprinting temperature variation
- Nanoimprint lithography
- Rhodamine B molecule