Method of manufacturing a semiconductor device comprising first and second field stop zone portions

A method of manufacturing a semiconductor device in a semiconductor body, the method comprising:

• forming a drift zone of a first conductivity type on a semiconductor substrate;
• processing the semiconductor body at a first surface of the semiconductor body;
• thinning the semiconductor body by removing material of the semiconductor substrate from a second surface of the semiconductor body opposite to the first surface;
• forming a first field stop zone portion of the first conductivity type between the second surface and the drift zone by implanting protons into the semiconductor body through the second surface and setting a vertical distance between an end-of-range peak of the protons and the second surface in a range from 5 μm to 70 μm, and further setting an average doping concentration of the first field stop zone portion greater than 120% of an average doping concentration of the drift zone;
• forming a second field stop zone portion of the first conductivity type by implanting protons at one or more energies into the semiconductor body through the second surface, wherein a deepest end-of-range peak of the protons is set in the first field stop zone portion at a vertical distance to a transition between the drift zone and the first field stop zone portion in a range from 3 μm to 60 μm;
• and
• annealing the semiconductor body by thermal processing
• wherein q1 equals an integral of an ionized dopant charge along a vertical extension of the first field stop zone portion and q2 equals an integral of an ionized dopant charge along a vertical extension of the second field stop zone portion, and wherein a doping concentration profile of the first and second field stop zone portions is adjusted to set a ratio of q2 to q1 in a range from 1 to 8.

A method of manufacturing a semiconductor device in a semiconductor body, the method comprising:

• forming a first field stop zone portion of a first conductivity type on a semiconductor substrate;
• forming a drift zone of the first conductivity type on the first field stop zone portion, wherein an average doping concentration of the drift zone is set smaller than 80% of an average doping concentration of the first field stop zone portion;
• processing the semiconductor body at a first surface of the semiconductor body;
• thinning the semiconductor body by removing material of the semiconductor substrate from a second surface of the semiconductor body opposite to the first surface;
• forming a second field stop zone portion of the first conductivity type by introducing dopants of the first conductivity type into the semiconductor body through the second surface, wherein the dopants are deep-level dopants;
• and
• annealing the semiconductor body by thermal processing,
• wherein the second field stop zone portion is formed by introducing the dopants of the first conductivity type into the semiconductor body through the second surface after the thinning of the semiconductor body.

A method of manufacturing a semiconductor device in a semiconductor body, the method comprising:

• forming a drift zone of a first conductivity type on a semiconductor substrate;
• processing the semiconductor body at a first surface of the semiconductor body;
• thinning the semiconductor body by removing material of the semiconductor substrate from a second surface of the semiconductor body opposite to the first surface;
• forming a first field stop zone portion of the first conductivity type between the second surface and the drift zone by implanting protons into the semiconductor body through the second surface and setting a vertical distance between an end-of-range peak of the protons and the second surface in a range from 5 μm to 70 μm and further setting an average doping concentration of the first field stop zone portion greater than 120% of an average doping concentration of the drift zone;
• forming a second field stop zone portion of the first conductivity type by introducing dopants of the first conductivity type into the semiconductor body through the second surface, wherein the dopants are deep-level dopants;
• and
• annealing the semiconductor body by thermal processing
• wherein after the annealing, a doping concentration profile of the second field stop zone portion comprises a plurality of local maximums wherein the doping concentration decreases on either side the respective local maximum.