PHOTOMASK PROVIDED WITH AN ESD-PRECLUDING ENVELOPE

摘要

A photomask (1) comprises a transmissive base plate (2), a first side of which is provided with a layer of a metallic mask material (4). In this layer, a mask pattern (6) is formed which is enclosed in an outer region (5) of mask material. The photomask is encapsulated in a protection layer (9) of transmissive and conductive material, which, on the first side of the base plate, is formed at such a distance from said first side that said protection layer remains free of the mask pattern.The photomask is thus protected against electrostatic discharges which could damage the mask pattern, and the projection of the mask pattern is not adversely affected.