Abstract: A photomask useful as stencil or reticle comprises a thin layer, which includes regions of different optical transmissivity for light radiation of a predetermined spectral range. The layer consists of silicon or any other suitable semiconductor material, and the regions of different transmissivity consist essentially of the monocrystalline or amorphous phase of the mask material. The photomask may be manufactured by irradiating a thin layer of monocrystalline silicon with a focussed ion beam to convert the silicon within the irradiated regions into the amorphous phase.

Abstract: To provide for effective doping and obtain substantial conductivity change in amorphous semiconductor material, typically silicon, a body of said material is raised to a temperature above about 20.degree. C. and below the recrystallization temperature, for example in the range of between 100.degree. C., preferably above 200.degree.-250.degree. C. and below about 450.degree. C. during the ion implantation. The doping ions are, for example for silicon, of groups III and V of the periodic system, particularly boron and phosphorus. Semiconductor junctions can be made by this process by selectively doping spatially limited regions of the semiconductor body to thereby produce semiconductor components by doping with ions of different characteristics, for example of different conductivity type.