A new mask blank deposition tool

A new ion beam sputter deposition tool (Seg-IonSys-1900) for EUV mask blanks has been developed. Different novel concept ideas were implemented in the tool to overcome the actual critical points of low particle generation and their embedding in the deposited layers, high homogeneity of layer thickness and very high mask blank throughput. For this it has been used a vertical position of the mask blanks for transportation and deposition without any kinds of substrate clamping. The Mo and Si layer deposition were realized by a segment controlled linear electron cyclotron resonance ion beam source. With it the ion beam profile can be adjusted to homogenize the layer thickness without rotation of the substrate. The focussed three grid system cause a deposition rate at 1000 eV Xe ions of 0.25 nm/s for Mo and 0.35 nm/s for Si. Thus, by optimization of the process parameters a 50 Mo/Si multilayer stack can be produced within 1 h.