Shadow projecting mask for ion implantation and lithography by ion beam radiation

摘要

1. Shadow projection mask comprising a thin P+ -doped silicon layer (1) with through holes adapted to the mask pattern, and a grid (2) supporting this layer (1) in areas without holes and consisting of silicon ribs doped differently from the silicon layer (1) having on at least its side (in the following called upper side) facing away from the grid (2) an ion-absorbing layer, and where at least the surface exposed to ion radiation is electrically and thermally conductive ; characterized in that where it is to be exposed to the ion beams the coating of the silicon frame (1, 2) of the mask consists either of a material that is both resistant to the mechanical attack of the ions and ion-absorbing, or of a double layer where the layer exposed to the ion radiation consists of a material resistant to the mechanical attack of the ions, and the layer facing the silicon frame of an ion-absorbing material with the coating, taking into consideration the ion energy and absorption characteristics being of such a thickness that no ions penetrate into the silicon, and that the mask side comprising the grid (2) (in the following called lower side) having a coating preferably identical with that deposited on the upper side-which compensates the mechanical tension created by the coating of the upper side.