Fin pitch scaling for high voltage devices and low voltage devices on the same wafer
View Patent ↗A semiconductor device is provided that includes a first plurality of fin structures having a first width in a first region of a substrate, and a second plurality of fin structures having a second width in a second region of the substrate, the second width being less than the first width. A first gate structure is formed on the first plurality of fin structures including a first high-k gate dielectric that is in direct contact with a channel region of the first plurality of fin structures and a first gate conductor. A second gate structure is formed on the second plurality of fin structures including a high voltage gate dielectric that is in direct contact with a channel region of the second plurality of fin structures, a second high-k gate dielectric and a second gate conductor.
1. A method of forming a semiconductor device comprising:
forming a plurality of spacers on a semiconductor substrate having a first width using spacer image transfer;
forming a block mask over a first grouping of the plurality of the spacers;
applying an isotropic etch to a second grouping of the plurality of spacers not covered by the block mask while the block mask is over the first grouping of the plurality of spacers, wherein the isotropic etch reduces a width of at least one spacer in the second group of spacers to a second width that is less than the first width;
removing the block mask; and
etching a plurality of fin structures from the semiconductor containing substrate using the first grouping of spacers having the first width and the second grouping of spacers having the second width, the first plurality of fin structures having said first width provides a channel region for semiconductor devices having a first applied voltage, and the second plurality of fin structures having said second width provides a channel region for semiconductor devices having a second applied voltage that is greater than the first applied voltage.
2. The method of claim 1 further comprising forming a high voltage dielectric layer on said second plurality of fin structures.
3. The method of claim 2 , wherein forming the high voltage dielectric layer comprises blanket depositing said high voltage dielectric layer on said first plurality of fin structures and said second plurality of fin structures, and removing the high voltage dielectric layer from the first plurality of fin structures using a selective etch.
4. The method of claim 3 , wherein the high voltage dielectric layer is an oxide.
5. The method of claim 3 , wherein the high voltage dielectric layer has a thickness ranging from 3 nm to 7 nm.
6. The method of claim 3 further comprising forming a first high-k gate dielectric layer directly on the channel region of the first plurality of fin structures, and forming a second high-k dielectric layer directly on the high voltage dielectric layer that is present directly on the channel region of the second plurality of fin structures.
7. The method of claim 6 further comprising forming a gate conductor on the first and second high-k gate dielectric layers.
8. The method of claim 1 , wherein the first applied voltage is less than 1.2 eV, and the second applied voltage is greater than 2.0 eV.