A glass substrate-holding tool, adapted to be employed during the production of a reflective mask blank for EUV lithography, includes an electrostatic chuck and a supporting member. The bristle assembly may include a base and a plurality of bristles. The slot is located between the retaining ring and the bearing. The sending node may request bandwidth for the QoS flow from the network controller. Furthermore, by the addition of internal voids, the wafer reduces or eliminates the lateral propagation of acoustic energy through the wafer. The invention also relates to the cooling element made in the mould, inside which cooling pipes made of nickel copper are placed during fabrication.