Abstract: An apparatus support (11) with a damping characteristic comprises a rigid reinforcing component, in particular a steel plate (19), encapsulated by a body (16) of compliant material, particularly a composite of particulate mineral material and synthetic binder. The plate (19) defines an opening (19a) at spacing from the upper side of the body (16) and a mounting ring (21) is embedded in the body so as to be disposed at least partly above the opening. The ring (21) has a peripheral flange (21a) which is spaced from the plate (19) and from the upper side of the body and overlaps the plate in vertical projection. Material of the body is thus disposed above the flange (21a) and also sandwiched between the flange and the plate so that a damping zone is present around the ring both above and below the flange.

Abstract: A method of producing an array of islands (12) on concentric tracks (13) on a rotating substrate by selective exposure of an electron-sensitive surface of the substrate to an electron beam comprises directing the beam onto a point (A) on the surface within a zone of action of the beam and deflecting the beam in the sense (31) of substrate rotation to remain on the point until the point (A?) has received an electron dose from the beam. The beam is then redirected onto a further point (B or T) at a spacing from the preceding point (A?) and dosed by the beam in similar manner. The redirection and deflection procedure is repeated for at least one substrate revolution, preferably several revolutions, so that points are dosed along at least one of the tracks (13a), preferably several of the tracks (13a to 13j).

Abstract: An apparatus support (11) with a damping characteristic comprises a rigid reinforcing component, in particular a steel plate (19), encapsulated by a body (16) of compliant material, particularly a composite of particulate mineral material and synthetic binder. The plate (19) defines an opening (19a) at spacing from the upper side of the body (16) and a mounting ring (21) is embedded in the body so as to be disposed at least partly above the opening. The ring (21) has a peripheral flange (21a) which is spaced from the plate (19) and from the upper side of the body and overlaps the plate in vertical projection. Material of the body is thus disposed above the flange (21a) and also sandwiched between the flange and the plate so that a damping zone is present around the ring both above and below the flange.

Abstract: An electron beam lithography machine (10) comprises a base structure in the form of a plinth (14), a plurality of legs (22), which preferably include pneumatic damping elements (23), for supporting the plinth relative to a support surface (24), the legs defining a support plane (A) for the plinth, an electron beam column (11) carried by the plinth and a stage (17, 18) arranged in a vacuum chamber at the plinth to be movable substantially parallel to the support plane and to carry a workpiece (13) to be acted on by an electron beam generated by the column. The centre of gravity (25) of the stage, which can be movable along X and Y axes of a co-ordinate system of the machine, is disposed in or adjacent to the support plane so that a reaction force to the stage movement is oriented in the support plane or in an adjacent, parallel plane.

Abstract: An apparatus support structure (11) with a damping characteristic comprises a rigid steel frame resistant to loading in bending and tension, a cladding (16) encapsulating the frame, and an apparatus mounting ring (21). The cladding is formed by a solidified composite casting material which is based on particulate mineral or metallic material, for example, granite, and a synthetic binder, for example epoxy resin, and which has a compliance permitting damping of movement transmitted between the structure and apparatus mounted on the ring (21). The structure can be produced by encasing the frame and ring in a mould constructed in situ around the frame and filing the mould with the cladding material in fluid state.

Abstract: Movement-sensitive equipment (10), for example an electron beam lithography machine, is provided with an optical measuring system operable to measure the position of the equipment in a reference plane (A) so as to detect unintended displacement of the equipment in that plane, for example thermally induced shift of the lower end of an otherwise fixed electron beam column (11) of such a lithography machine. The system comprises an integral plate (17) of vitreous material provided with two mutually orthogonal reflective faces (19), with high optical accuracy, for reflecting laser or other measuring light beams. The plate (17) is adjustably and releasably mounted on the equipment (10) by a plurality of mounts (17) which permit accurate setting of the faces (19) relative to the plane (A) and allow removal of the plate as desired. The mounts (17) are designed to clamp the plate (17) in such a way as to avoid creation of stresses potentially causing cracks.