STRUCTURE AND METHOD FOR EFFECTIVE DEVICE WIDTH ADJUSTMENT IN FINFET DEVICES USING GATE WORKFUNCTION SHIFT

Embodiments of the present invention provide methods and structures by which the inherent discretization of effective width can be relaxed through introduction of a fractional effective device width, thereby allowing greater flexibility for design applications, such as SRAM design optimization. A portion of some fins are clad with a capping layer or workfunction material to change the threshold voltage (Vt) for a part of the fin, rendering that part of the fin electrically inactive, which changes the effective device width (Weff). Other fins are unclad, and provide maximum area of constant threshold voltage. In this way, the effective device width of some devices is reduced. Therefore, the effective device width is controllable by controlling the level of cladding of the fin.