Patent ID: 8530974
Filing Date: 2013-09-10
Classification: H01L

Abstract:
1. A complementary metal oxide semiconductor (CMOS) structure having multiple threshold voltage devices, the structure comprising: a first transistor device and a second transistor device formed on a semiconductor substrate; and a set of vertical oxide spacers selectively formed only for the first transistor device, the set of vertical oxide spacers being in direct contact with a high-k gate dielectric layer of the first transistor device such that the first transistor device has a shifted threshold voltage with respect to the second transistor device, and the set of vertical oxide spacers provides a source of diffused oxygen atoms to the high-k gate dielectric layer so as to result in the shifted threshold voltage with respect to the second transistor device; wherein the high-k gate dielectric layer for the first transistor device has a vertical portion that directly abuts the set of vertical oxide spacers for the first transistor device, and wherein the vertical portion of the high-k gate dielectric layer for the first transistor device is disposed between the set of vertical oxide spacers for the first transistor device and a metal gate fill material, and wherein the high-k gate dielectric layer for the second transistor device has a vertical portion that directly abuts a set of nitride spacers for the second transistor device, and wherein the vertical portion of the high-k gate dielectric layer for the second transistor device is disposed between the set of nitride spacers for the second transistor device and the metal gate fill material.