The present disclosure relates to a semiconductor device includes first and second source/drain (S/D) regions doped with lead (Pb) at a first dopant concentration. The semiconductor device also includes a channel region between the first and second S/D regions, where the channel region is doped with Pb at a second dopant concentration that is lower than the first dopant concentration. The semiconductor device further includes first and second S/D contacts in contact with the first and second S/D regions, respectively. The semiconductor device also includes a gate electrode over the channel region.