Laser doping of semiconductors

Process for the direct doping of a silicon substrate, characterised in that

• a) a low-viscosity doping ink which is suitable as sol-gel for the formation of oxide layers and comprises at least one doping element selected from the group boron, gallium, silicon, germanium, zinc, tin, phosphorus, titanium, zirconium, yttrium, nickel, cobalt, iron, cerium, niobium, arsenic and lead is printed onto the substrate surface, over the entire surface or selectively, and dried,
• b) this step is optionally repeated with a low-viscosity ink of the same or different composition,
• c) doping by diffusion is optionally carried out by temperature treatment at temperatures in the range from 750 to 1100° C.,
• d) doping of the substrate is carried out by laser irradiation, and
• e) repair of the damage induced in the substrate by the laser irradiation is optionally carried out by a tubular furnace step or in-line diffusion step at elevated temperature,
• and
• f) when the doping is complete, the glass layer formed from the applied ink is removed again,
• where steps b) to e) can, depending on the desired doping result, be carried out in a different sequence and optionally repeated.