Patent ID: 6891244

Claim:
A method of manufacturing a plug structure having low contact resistance on a substrate having a first dopant area, wherein the first dopant area is a positive-type dopant area, and the method comprising: forming a dielectric layer on the substrate; forming a contact window within the dielectric layer wherein a bottom of the contact window partially exposes the first dopant area; forming a second dopant area within the substrate wherein a part of the second dopant area is overlaid with a part of the first dopant area, and the second dopant area is a positive-type dopant area; forming a first barrier layer having a barrier element on a border between the contact window and the second dopant area, wherein the barrier element is germanium; forming a second barrier layer on a sidewall and the bottom of the contact window; forming a metal plug within the contact window, and filling the contact window with the metal plug; forming a conductive interconnecting line on the dielectric layer; and performing a rapid thermal annealing.