Homogeneous lithium fluoride films as a high resolution electron beam resist

As a new high resolution electron beam resist, homogeneous and fine-crystalline lithium fluoride films were fabricated. For this purpose, a special evaporation process was developed. The advantage of lithium fluoride is the relatively low critical exposure dose, compared with other metal halides. The exposure characteristics of this resist have been studied and the high resolution capability in the range below 10nm is demonstrated. The critical exposure dose for a single line is between 200 and 800nC/cm, depending on film thickness and substrate. The properties of these films in standard RIE-processes were investigated and pattern transfer into SiO 2 was performed.