Method for producing structured metal contacts on a semiconductor substrate

Method for producing structured metallic contacts

• (9) on a semiconductor substrate (1, 2), in which
• a layer consisting of one or a layer sequence (4, 5) consisting of multiple metallic contact materials, by which the contacts (9) are at least partially formed, is deposited on the full surface of the semiconductor substrate (1, 2),
• a further metallic contact material (7) is deposited on the layer or layer sequence (4, 5) consisting of the one or more metallic contact materials in predetermined contact regions, by which a geometry of the metallic contacts (9) is defined,
• the layer or layer sequence (4, 5) then undergoes a thermal treatment, in which the one or more contact materials is/are alloyed into the semiconductor substrate (1, 2) in the predetermined contact regions, to form a low impedance contact from a Schottky contact between the one or more metallic contact materials and the semiconductor substrate (1, 2), and
• the layer or layer sequence (4, 5) is then removed again between the predetermined contact regions,
• wherein the thermal treatment is carried out by scanning the layer or layer sequence (4, 5) with a laser beam, and the metallic contact material of the layer or of a topmost layer of the layer sequence (4, 5), the further metallic contact material (7) and a laser wavelength of the laser beam are tuned to each other in such a way that the metallic contact material of the layer or of the topmost layer of the layer sequence (4, 5) has a reflectivity for the laser beam that is at least 3 times higher than that of the further metallic contact material (7).