Patent ID: 7642574
Filing Date: 2010-01-05
Classification: H01L

Abstract:
1. A structure comprising a principal field-effect transistor (“FET”) which comprises: a principal channel zone of principal body material of a semiconductor body having an upper semiconductor surface, the body material being of a first conductivity type; a pair of principal source/drain (“S/D”) zones situated in the semiconductor body along the upper semiconductor surface, laterally separated by the channel zone, and being of a second conductivity type opposite to the first conductivity type, a principal well portion of the body material extending below the channel and S/D zones, the well portion defined substantially by principal semiconductor well dopant of the first conductivity type and being more heavily doped than overlying and underlying portions of the body material, the well dopant having a concentration that reaches a principal subsurface maximum along a location no more than 10 times deeper below the upper semiconductor surface than a specified one of the S/D zones such that all dopant of the first conductivity type in the body material has a concentration that decreases by at least a factor of 10 in moving upward from the location of the subsurface maximum in the concentration of the well dopant to the specified S/D zone; a principal gate dielectric layer overlying the channel zone; and a principal gate electrode overlying the gate dielectric layer above the channel zone.