A solar cell manufacturing process, comprising the process steps: - Providing a semiconductor wafer (3, 31) with at least one dielectric layer (5, 35), - forming a metal layer (7, 37) on the dielectric layer (5, 35) and a contact structure arranged in the dielectric layer (5, 35) so that the contact structure provides an electrical connection between the metal layer (7,37) and the semiconductor wafer (3, 33), wherein at least one first structure (9a,39a) having a minimum dimension and at least one second structure (9b,39b) having a maximum dimension are formed as contact structure, so that the minimum dimension of the first structure (9a, 39a) is greater than the maximum dimension of the second structure (9b, 39b), wherein the minimum dimension and the maximum dimension are defined along a surface of the semiconductor wafer (3, 33), characterized in that the formation of the metal layer and the contact structure comprises the following process steps: - Applying at least one metal paste inert to the dielectric layer and at least one metal paste reactive to the dielectric layer on the dielectric layer so that the metal paste reactive to the dielectric layer forms at least one first area and/ or at least a second area in the metal paste inert to the dielectric layer; and - firing so that the metal paste reactive to the dielectric layer and forming the first area and the second area penetrates the dielectric layer and forms the first structure and / or the second structure. - Providing a semiconductor wafer (3, 31) with at least one dielectric layer (5, 35), - forming a metal layer (7, 37) on the dielectric layer (5, 35) and a contact structure arranged in the dielectric layer (5, 35) so that the contact structure provides an electrical connection between the metal layer (7,37) and the semiconductor wafer (3, 33), wherein at least one first structure (9a,39a) having a minimum dimension and at least one second structure (9b,39b) having a maximum dimension are formed as contact structure, so that the minimum dimension of the first structure (9a, 39a) is greater than the maximum dimension of the second structure (9b, 39b), wherein the minimum dimension and the maximum dimension are defined along a surface of the semiconductor wafer (3, 33), characterized in that the formation of the metal layer and the contact structure comprises the following process steps: - Applying at least one metal paste inert to the dielectric layer and at least one metal paste reactive to the dielectric layer on the dielectric layer so that the metal paste reactive to the dielectric layer forms at least one first area and/ or at least a second area in the metal paste inert to the dielectric layer; and - firing so that the metal paste reactive to the dielectric layer and forming the first area and the second area penetrates the dielectric layer and forms the first structure and / or the second structure. - Applying at least one metal paste inert to the dielectric layer and at least one metal paste reactive to the dielectric layer on the dielectric layer so that the metal paste reactive to the dielectric layer forms at least one first area and/ or at least a second area in the metal paste inert to the dielectric layer; and - firing so that the metal paste reactive to the dielectric layer and forming the first area and the second area penetrates the dielectric layer and forms the first structure and / or the second structure.