Method of manufacturing a super-junction semiconductor device

摘要

A method of manufacturing a super-junction semiconductor device is disclosed that allows forming a high concentration layer with high precision and improves the trade-off relationship between the Eoff and the dV/dt. The method comprises a step of forming a parallel pn layer and a step of forming a proton irradiated layer in the upper region of the pn layer. Then, heat treatment is conducted on the proton irradiated layer for transforming the protons into donors to form a high concentration n type semiconductor layer.

主权项

1. A method of manufacturing a super-junction semiconductor device comprising steps of:
forming a first semiconductor layer of a first conductivity type on a semiconductor substrate by means of an epitaxial growth process, wherein the first semiconductor layer has a lower concentration of impurities than the substrate; forming a trench in the first semiconductor layer from a surface of the first semiconductor layer toward the semiconductor substrate; forming a parallel pn layer of a super-junction structure by filling the trench with an epitaxially grown second semiconductor layer of a second conductivity type; forming a device surface structure on the surface region of the parallel pn layer; decreasing a thickness of the semiconductor substrate by grinding a back side of the semiconductor substrate after the step of forming the device surface structure; forming a heavy particle irradiation layer by irradiating heavy particles from the back side of the semiconductor substrate into a portion of the parallel pn layer beneath the device surface structure after the step of decreasing the thickness of the semiconductor substrate; and forming a third semiconductor layer of the first conductivity type with an impurity concentration lower than that of the second semiconductor layer and higher than that of the first semiconductor layer by transforming the heavy particles in the heavy particle irradiation layer formed by the heavy particle irradiation into donors through a heat treatment process, wherein, the third semiconductor layer is adjacent to the device surface structure.