Semiconductor device having gradient doping profile

摘要

The present disclosure provides a method of fabricating a semiconductor device. The method includes forming a gate over a substrate. The method includes performing a first implantation process to form a first doped region in the substrate, the first doped region being adjacent to the gate. The method includes performing a second implantation process to form a second doped region in the substrate, the second doped region being formed farther away from the gate than the first doped region, the second doped region having a higher doping concentration level than the first doped region. The method includes removing portions of the first and second doped regions to form a recess in the substrate. The method includes epitaxially growing a third doped region in the recess, the third doped region having a higher doping concentration level than the second doped region.

主权项

1. A semiconductor device, comprising:
a gate disposed over a substrate, the gate including a gate electrode; a spacer disposed on a sidewall of the gate, wherein the sidewall of the gate is partially defined by the gate electrode; a first doped region disposed in the substrate, wherein a portion of the first doped region is disposed beneath the gate; a second doped region disposed in the substrate, wherein a portion of the second doped region is disposed beneath the spacer but not the gate, the second doped region being more heavily doped than the first doped region; and a third doped region disposed in the substrate, wherein the third doped region is aligned with the spacer and is not disposed below the gate, the third doped region being more heavily doped than the second doped region; wherein: the second doped region extends further into the substrate than the first doped region; and the third doped region extends further into the substrate than the second doped region.