Submicron Thermocouple Measurements of Electron-Beam Resist Heating

Pattern distortion caused by resist heating is believed to contribute significantly to errors in feature size and pattern placement. A number of models have been proposed to predict the temperature rise of resist heating but experimental results are scarce. We fabricated and calibrated thin film gold/ nickel thermocouples with (400 nm)2 junction size and used these to measure work-piece heating during electron-beam exposure. Irradiation by a 15 kV electron beam of 600 nA and 2 mm radius caused a temperature rise of 70 K, about 15% lower than the calculated result. The discrepancy may be due to the differences between the energy deposition profiles used in modeling and those prevailing in the experiments.