Manufacturing method of power transistor device with super junction

摘要

The present invention provides a manufacturing method of a power transistor device. First, a semiconductor substrate of a first conductivity type is provided, and at least one trench is formed in the semiconductor substrate. Next, the trench is filled with a dopant source layer, and a first thermal drive-in process is performed to form two doped diffusion regions of a second conductivity type in the semiconductor substrate, wherein the doping concentration of each doped diffusion region close to the trench is different from the one of each doped diffusion region far from the trench. Then, the dopant source layer is removed and a tilt-angle ion implantation process and a second thermal drive-in process are performed to adjust the doping concentration of each doped diffusion region close to the trench.

主权项

1. A manufacturing method of a power transistor device with a super junction, comprising:
providing a semiconductor substrate of a first conductivity type; forming at least one trench in said semiconductor substrate; filling a dopant source layer into said trench, wherein said dopant source layer comprises a plurality of dopants of a second conductivity type different from said first conductivity type; performing a first thermal drive-in process to diffuse said dopants into said semiconductor substrate, so as to form two doped diffusion regions in said semiconductor substrate at both sides of said trench, wherein the doping concentration of each said doped diffusion region close to the sidewall of said trench is different from the doping concentration of each said doped diffusion region far from the sidewall of said trench; removing said dopant source layer; and performing a tilt-angle ion implantation process and a second thermal drive-in process to adjust the doping concentration of each said doped diffusion region close to the sidewall of said trench.