Patent ID: 7838369

Claim:
A method comprising: introducing first semiconductor dopant of a first conductivity type into a semiconductor body to define a principal well portion of the first conductivity type for a principal field-effect transistor (“FET”) such that material of the semiconductor body (a) overlies the well portion as it exists directly after the act of introducing the first dopant of the first conductivity type and (b) is then of a second conductivity type opposite to the first conductivity type; defining, for the FET, a principal gate electrode above, and vertically separated by principal gate dielectric material from, material of the semiconductor body intended to be a principal channel zone of the first conductivity type; subsequently introducing first semiconductor dopant of the second conductivity type into the semiconductor body to form, for the FET, principal first and second source/drain (“S/D”) zones of the second conductivity type laterally separated by material of the semiconductor body intended to be the channel zone; and performing additional processing to complete fabrication of the FET such that (a) part of the first dopant of the first conductivity type diffuses upward into the material of the semiconductor body above the well portion during the act of performing additional processing so as to cause substantially all of the material of the semiconductor body above the well portion not significantly subjected to other doping of the first or second conductivity type subsequent to the act of introducing the first dopant of the first conductivity type to be converted to the first conductivity type and (b) the channel zone is at least partially constituted with at least part of the so-converted material of the semiconductor body above the well portion.