摘要 |
An arrangement for masked beam lithography by means of electrically charged particles for the imaging of structures of a mask on a substrate arranged behind it, with a substantially punctiform particle source (Q) and an extraction system (Ex) for a specific type of charged particles which leave the source (Q) in the form of a divergent particle beam, and with an electrode arrangement (B, B', El1, El2, E3, . . . Eln) for concentrating the divergent particle beam into a particle beam which is at least approximately parallel, by means of which an electrostatic acceleration field (E) is generated, the potential (U) of which in the beam direction has a constant gradient at least in parts and perpendicular to the beam direction is substantially constant at least within the beam cross-section. The electrode arrangement can be formed for example by a plurality of coaxial ring electrodes (El1, El2, El3, . . . Eln) which are disposed at intervals behind one another in the beam direction, by a coaxial hollow cylinder which is aligned in the beam direction or a grating with a predetermined constant electrical resistance per unit of length, or by a plurality of longitudinal bars which are aligned in the beam direction, disposed parallel on surface of an imaginary coaxial cylinder with a predetermined constant electrical resistance per unit of length.
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