Semiconductor device and method for manufacturing semiconductor device

A semiconductor device comprising:

• a first-conductivity-type drift layer;
• a second-conductivity-type base layer that is provided on a first main surface of the drift layer and has an impurity concentration more than that of the drift layer;
• a first-conductivity-type emitter layer that is provided on the first main surface of the drift layer so as to come into contact with the base layer and has an impurity concentration more than that of the base layer;
• an insulating film that comes into contact with the drift layer, the base layer, and the emitter layer;
• a gate electrode that is adjacent to the drift layer, the base layer, and the emitter layer through the insulating film;
• a second-conductivity-type collector layer that is provided on a second main surface of the drift layer and has an impurity concentration more than that of the drift layer;
• and
• a first-conductivity-type broad buffer region that is provided in the drift layer and has an impurity concentration more than that of the drift layer and in which a local maximum value of an impurity concentration distribution is less than the base layer and the collector layer,
• wherein the total amount of the net doping concentration of the broad buffer region is equal to or more than 4.8×1011 atoms/cm2 and equal to or less than 1.0×1012 atoms/cm2, and
• wherein the resistivity ρ0 (Ωcm) of the drift layer satisfies 0.12V0≦ρ00.25V0 with respect to a rated voltage V0 (V).

A method of manufacturing a semiconductor device including a first first-conductivity-type semiconductor layer, a second second-conductivity-type semiconductor layer that is provided on one main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer, a third first-conductivity-type semiconductor layer that is provided on the other main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer, and a first-conductivity-type broad buffer region that is provided in the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer and in which a local maximum value of an impurity concentration distribution is less than the impurity concentration of the second semiconductor layer and the third semiconductor layer, comprising:

• a first forming step of forming the second semiconductor layer on the one main surface of the first semiconductor layer;
• and
• a second forming step of irradiating the second semiconductor layer on the first semiconductor layer with a hydrogen ion at a projected range to the first semiconductor layer and performing a heat treatment at a temperature of 300° C. or more to 550° C. or less, thereby forming the broad buffer region in the first semiconductor layer,
• wherein, in the second forming step, the broad buffer region having a total net doping concentration of 4.8×1011 atoms/cm2 or more to 1.0×1012 atoms/cm2 or less is formed in the first semiconductor layer, and
• wherein the resistivity ρ0 of the first semiconductor layer satisfies 0.12V0≦ρ0≦0.25V0 with respect to a rated voltage V0 (V).

A method of manufacturing a semiconductor device including a first first-conductivity-type semiconductor layer, a second second-conductivity-type semiconductor layer that is provided on one main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer, a third first-conductivity-type semiconductor layer that is provided on the other main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer, and a first-conductivity-type broad buffer region that is provided in the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer and in which a local maximum value of an impurity concentration distribution is less than the impurity concentration of the second semiconductor layer and the third semiconductor layer, comprising:

• a second forming step of irradiating the other main surface of the first semiconductor layer with a hydrogen ion at a projected range to a portion of the first semiconductor layer deeper than a position where the third semiconductor layer is to be formed by a subsequent step and performing a heat treatment at a temperature of 300° C. or more to 550° C. or less, thereby forming the broad buffer region in the first semiconductor layer,
• wherein, in the second forming step, the broad buffer region having a total net doping concentration of 4.8×1011 atoms/cm2 or more to 1.0×1012 atoms/cm2 or less is formed in the first semiconductor layer, and
• the resistivity ρ0 of the first semiconductor layer satisfies 0.12V0≦ρ0≦0.25V0 with respect to a rated voltage V0 (V).