Patent ID: 7727868

Claim:
A method of forming a doped semiconductor region comprising: forming a first conductivity type doped semiconductor well, including introducing a first dopant element and a second dopant element, both of a first conductivity type to a selected region of a semiconductor surface; forming a second conductivity type doped semiconductor region substantially within the first conductivity type doped semiconductor well, including introducing a third dopant element and a fourth dopant element, both of a second conductivity type; annealing the selected region of the semiconductor surface; controlling a diffusion rate of the first and second dopant elements by selecting a combination of dopant elements that minimize lattice strain to approach an unstrained condition of an undoped semiconductor region in the selected region of the semiconductor surface; and controlling a diffusion rate of the third and fourth dopant elements by selecting a combination of dopant elements that minimize lattice strain to approach an unstrained condition of an undoped semiconductor region in the selected region of the semiconductor surface.