Semiconductor structure and fabrication method thereof

摘要

A method for fabrication of a semiconductor device is provided. A first type doped body region is formed in a first type substrate. A first type heavily-doped region is formed in the first type doped body region. A second type well region and second type bar regions are formed in the first type substrate with the second type bar regions between the second type well region and the first type doped body region. The first type doped body region, the second type well region, and each of the second type bar regions are separated from each other by the first type substrate. The second type bar regions are inter-diffused to form a second type continuous region adjoining the second type well region. A second type heavily-doped region is formed in the second type well region.

主权项

1. A semiconductor structure, comprising:
a first type substrate; a first type body doped region on the first type substrate; a first type heavily-doped region on the first type body doped region; a second type well region on the first type substrate; a diffused second type well region between the second type well region and first type body doped region and adjoined to the second type well region, wherein a second type impurity concentration of the diffused second type well region is lower than a second type impurity concentration of the second type well region; a second type heavily-doped region on the second type well region; an isolation structure on the diffused second type well region, wherein a doped depth of the diffused second type well region is substantially equal to that of the second type well region, and wherein the isolation structure directly adjoins the second type heavily-doped region and the diffused second type well region; and a gate structure on the first type substrate between the first type heavily-doped region and isolation structure, wherein the second type well region extends laterally beneath the second type heavily-doped region, and the diffused second type well region extends laterally beginning from the second type well region beneath the isolation structure without passing beneath the first type heavily-doped region, arranged such that a difference in the second type impurity concentration between the second type well region and the diffused second type well region obtains a field buffering effect.