A semiconductor device, wherein the semiconductor device comprises: an N-type drift layer; an N-type field stop layer, adjacent to the N-type drift layer, wherein a density of free electrons at the N-type field stop layer is higher than a density of free electrons at the N-type drift layer; a P-type collector layer, disposed on a surface that is of the field stop layer and that faces away from the N-type drift layer; a P-type base layer, disposed on a surface that is of the N-type drift layer and that faces away from the field stop layer; an N-type emitter layer, disposed on a surface that is of the P-type base layer and that faces away from the N-type drift layer; a gate, connected to the P-type base layer through an oxide layer; the N-type field stop layer comprises first impurity particles and second impurity particles, and a radius of the second impurity particles is greater than a radius of the first impurity particles; and the N-type field stop layer comprises multiple doping density peaks of the first impurity particles and multiple doping density peaks of the second impurity particles, wherein the multiple doping density peaks of the second impurity particles are located along a depth direction defined from the field stop layer to the N-type drift layer and the multiple doping density peaks of the second impurity particles are extending away from the P-type collector layer, each doping density peak of the second impurity particles having a height that decreases along the depth direction, and the multiple doping density peaks of the first impurity particles are located along the depth direction and extending away from the multiple doping density peaks of the second impurity particles; and wherein one doping density peak of the first impurity particles that is adjacent to the N-type drift layer along the depth direction is higher than any other doping density peak of the first impurity particles; wherein the first impurity particles are hydrogen ions or helium ions, and the second impurity particles are phosphorus atoms or arsenic atoms. an N-type drift layer; an N-type field stop layer, adjacent to the N-type drift layer, wherein a density of free electrons at the N-type field stop layer is higher than a density of free electrons at the N-type drift layer; a P-type collector layer, disposed on a surface that is of the field stop layer and that faces away from the N-type drift layer; a P-type base layer, disposed on a surface that is of the N-type drift layer and that faces away from the field stop layer; an N-type emitter layer, disposed on a surface that is of the P-type base layer and that faces away from the N-type drift layer; a gate, connected to the P-type base layer through an oxide layer; the N-type field stop layer comprises first impurity particles and second impurity particles, and a radius of the second impurity particles is greater than a radius of the first impurity particles; and the N-type field stop layer comprises multiple doping density peaks of the first impurity particles and multiple doping density peaks of the second impurity particles, wherein the multiple doping density peaks of the second impurity particles are located along a depth direction defined from the field stop layer to the N-type drift layer and the multiple doping density peaks of the second impurity particles are extending away from the P-type collector layer, each doping density peak of the second impurity particles having a height that decreases along the depth direction, and the multiple doping density peaks of the first impurity particles are located along the depth direction and extending away from the multiple doping density peaks of the second impurity particles; and wherein one doping density peak of the first impurity particles that is adjacent to the N-type drift layer along the depth direction is higher than any other doping density peak of the first impurity particles; wherein the first impurity particles are hydrogen ions or helium ions, and the second impurity particles are phosphorus atoms or arsenic atoms.