SETT ATT HALLA TUNNA ARBETSSTYCKEN

摘要

A laminar article (14) is held in a planar configuration by urging it, for example by means of a vacuum (applied via 16) against a plurality of small-area abutments (18) which define a planar surface. The smallness of the area of the abutments (18) reduces the probability of there being any intervening dirt particles to perturb the planarity of the article (14) and there is a tendency for any such particles to be squeezed out. Preferably the article (14) is given a slight lateral movement after bringing it into contact with the abutments (18) to dislodge remaining intervening dirt particles. The invention is particularly applicable to holding semiconductor wafers during pattern exposure but may be used to hold workpieces during polishing, grinding or machining.