Gate formation with varying work function layers
First Claim
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1. A method comprising:
- forming a first dielectric layer over a first fin and a second fin;
forming a recess in the first dielectric layer, the first fin and the second fin protruding above a bottom of the recess;
forming a first work function layer over the first fin and the second fin;
forming a first patterned mask over the first work function layer, the first patterned mask terminating closer to the first fin than the second fin such that the first work function layer over the second fin is exposed, wherein forming the first patterned mask comprises;
forming a first masking layer over the first work function layer, the first masking layer filling the recess;
forming a first photoresist layer over the first masking layer;
patterning the first photoresist layer to form a first patterned photoresist layer; and
patterning the first masking layer using the first patterned photoresist layer as a mask;
removing the first work function layer from over the second fin and an area between the first fin and the second fin, the first work function layer terminating at a position closer to the first fin than the second fin;
removing the first patterned mask;
forming a second work function layer over the first work function layer and the second fin;
forming a second patterned mask over the second work function layer, the second patterned mask terminating closer to the second fin than the first fin such that the second work function layer over the second fin is exposed;
removing the second work function layer from over the second fin and an area between the first fin and the second fin, the second work function layer terminating at a position closer to the second fin than the first fin;
removing the second patterned mask;
forming a third work function layer over the second work function layer and the second fin; and
forming a metal layer over the third work function layer.
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Abstract
A structure and a method of forming are provided. A first work function layer is formed over a first fin and terminates closer to the first fin than an adjacent second fin. A second work function layer is formed over the first work function layer and terminates closer to the second fin than the adjacent second fin. A third work function layer is formed over the first work function layer and the second fin. A conductive layer is formed over the third work function layer.
3 Citations
20 Claims
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1. A method comprising:
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forming a first dielectric layer over a first fin and a second fin; forming a recess in the first dielectric layer, the first fin and the second fin protruding above a bottom of the recess; forming a first work function layer over the first fin and the second fin; forming a first patterned mask over the first work function layer, the first patterned mask terminating closer to the first fin than the second fin such that the first work function layer over the second fin is exposed, wherein forming the first patterned mask comprises; forming a first masking layer over the first work function layer, the first masking layer filling the recess; forming a first photoresist layer over the first masking layer; patterning the first photoresist layer to form a first patterned photoresist layer; and patterning the first masking layer using the first patterned photoresist layer as a mask; removing the first work function layer from over the second fin and an area between the first fin and the second fin, the first work function layer terminating at a position closer to the first fin than the second fin; removing the first patterned mask; forming a second work function layer over the first work function layer and the second fin; forming a second patterned mask over the second work function layer, the second patterned mask terminating closer to the second fin than the first fin such that the second work function layer over the second fin is exposed; removing the second work function layer from over the second fin and an area between the first fin and the second fin, the second work function layer terminating at a position closer to the second fin than the first fin; removing the second patterned mask; forming a third work function layer over the second work function layer and the second fin; and forming a metal layer over the third work function layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method comprising:
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forming a dielectric layer over a first fin and a second fin; and forming a recess in the dielectric layer, the first fin and the second fin protruding through a bottom of the recess; forming a first work function layer over the first fin, the first work function layer terminating closer to the first fin than the second fin; forming a second work function layer over the first work function layer and the first fin, the second work function layer terminating closer to the second fin than the first fin, wherein the first fin and the second fin are adjacent fins with no intervening fins interposed between the first fin and the second fin, wherein the first work function layer and the second work function layer are formed along sidewalls of the recess; forming a third work function layer over the second work function layer, the third work function layer extending over the second fin; and forming a metal layer over the third work function layer. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method comprising:
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forming a first conductive layer over a first fin, the first conductive layer terminating closer to the first fin than a second fin, wherein the first fin and the second fin extend above a shallow trench isolation, wherein the shallow trench isolation extends continuously between the first fin and the second fin along a shortest line between the first fin and the second fin; forming a second conductive layer over the first conductive layer, the second conductive layer extending over the first fin and terminating closer to the second fin than the first fin; forming a third conductive layer over the second conductive layer, the third conductive layer extending over the first fin and the second fin, the first conductive layer being interposed between the second conductive layer and the first fin; and forming a metal layer over the first fin and the second fin. - View Dependent Claims (17, 18, 19, 20)
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Specification