Influence of hydrogen silsesquioxane resist exposure temperature on ultrahigh resolution electron beam lithography

Performance of hydrogen silsesquioxane (HSQ) resist material with respect to the temperature during electron beam exposure was investigated. Electron beam exposure at elevated temperatures up to 90 degrees C shows sensitivity rise and slight contrast (gamma) degradation compared to lower temperature cases. Ultrahigh resolution structures formed at elevated temperatures manifest better uniformity together with aspect ratio improvement and less linewidth broadening with overdose. Potential mechanisms for observed phenomena are proposed.