A study of the formation of water marks from membrane-distilled water and ultrapure water

Effects of evaporation temperature on the formation of water marks left on a Si wafer were studied using membrane-distilled water and ultrapure water. The main constituent of water marks from membrane-distilled water was found to be liquid hydrocarbon, with some C = C bonds present, and when evaporation velocity was greater than about 20 kg/(m2•h) evaporation could take place without marks formation. Water marks from ultrapure water had a higher boiling point than those from membrane-distilled water and were left on a Si wafer even when the water was evaporated at a velocity of about 20kg/(m2• h).