NOVELTY - A solar cell comprises a silicon wafer (3) having a light-receiving front side (4) and a backside (6), where the silicon wafer has a basic doping, and is provided with an interdigital semiconductor pattern.    USE - The method is used to form a solar module.    ADVANTAGE - The method prevents large manufacturing costs. It is mechanically strong, and reduces recombination of charge carriers.    DETAILED DESCRIPTION - A solar cell comprises a silicon wafer having a light-receiving front side and a backside, where the silicon wafer has a basic doping, and is, at its backside, provided with an interdigital semiconductor pattern. The interdigital semiconductor pattern comprises a first pattern of a first diffusion zone(s) (9) having a first doping and a second pattern of a second diffusion zone(s) (10), separated from the first diffusion zone(s) and having a second doping that differs from the first doping. The second diffusion zone is arranged along the sides of a groove(s) (12) extending from the backside into the silicon wafer.    An INDEPENDENT CLAIM is also included for a method of manufacturing a solar cell comprising: providing a silicon wafer, and providing the silicon wafer at its backside with an interdigital semiconductor pattern by applying a doping paste containing a first dopant to obtain a pattern of an area(s) covered with doping paste; drying the doping paste; producing a pattern of a first diffusion zone(s) having a first doping by forcing at elevated temperature in a free oxygen-containing atmosphere, the first dopant to diffuse into the silicon wafer, and simultaneously producing a silicon oxide layer; etching part of the silicon oxide layer by applying a first etching agent in areas between the first diffusion zones, and removing the first etching agent and the etched silicon oxide layer to obtain a pattern of silicon oxide rims; etching part of the silicon wafer by applying a second etching agent between the silicon oxide rims, and removing the second etching agent and the etched silicon to obtain a pattern of a groove(s); producing a second diffusion zone having a second doping on the sides of the groove(s), the second doping differing from the first doping; and removing the doping paste and the remainder of the silicon oxide layer to obtain the interdigital semiconductor pattern.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-section of the solar cell.    Silicon wafer (3)    Front side (4)    Backside (6)    First diffusion zone (9)    Second diffusion zone (10)    Groove (12)    Interdigital contacting structure (13, 14)