Patent ID: 8163619
Filing Date: 2012-04-24
Classification: H01L

Abstract:
1. A method of fabricating a semiconductor structure from a semiconductor body having body material of a first conductivity type, the method comprising: defining a gate electrode above, and vertically separated by a gate dielectric layer from, a portion of the body material intended to be a channel zone; and subsequently introducing (i) semiconductor dopant of a second conductivity type opposite to the first conductivity type into the semiconductor body to define first and second source/drain (“S/D”) zones of the second conductivity type laterally separated by the channel zone and (ii) pocket semiconductor dopant of the first conductivity type into at least the intended channel-zone portion of the body material to define a pocket portion of the body material more heavily doped than laterally adjacent material of the body material and extending largely along only the first of the S/D zones and into the channel zone so as to cause the channel zone to be asymmetric with respect to the S/D zones, the pocket dopant being so introduced at a plurality of different dopant-introduction conditions such that the pocket portion has a net dopant concentration which reaches a like plurality of respectively corresponding local maxima at respective locations spaced apart along an imaginary line that extends through the pocket portion generally perpendicular to the gate dielectric layer, a field-effect transistor comprising the S/D zones, the channel zone, the pocket portion, the gate dielectric layer, and the gate electrode.