Abstract: 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.

Abstract: A method and group of masks for manufacturing a device whereby illumination of a photoresist layer (4) takes place by subsequent illumination through partial masks (1) and 2). During these separate illuminations, complementary scales of grey are obtained in the connection region (7, 8) of the images (5, 6), the total illumination in the connection region (7, 8) being nevertheless complete. According to the invention, good results are obtained when the partial masks (1) and (2) have complementary transparency gradients in the ends (9, 10) corresponding to the scales of grey.