Abstract:
PROBLEM TO BE SOLVED: To provide an asymmetric semiconductor device, and to provide a method using a spacer scheme in manufacturing the same. SOLUTION: A semiconductor structure is provided that includes an asymmetric gate stack located on a surface of high-k gate dielectric. The asymmetric gate stack includes a first portion and a second portion, wherein the first portion has a different threshold voltage than the second portion. The first portion of the asymmetric gate stack includes, from bottom to top, a threshold voltage adjusting material and at least a first conductive spacer, while the second portion of the asymmetric gate stack includes at least a second conductive spacer over the gate dielectric. In some embodiments, the second conductive spacer is in direct contact with the underlying high-k gate dielectric, while, in other embodiments, the first and second conductive spacers are in direct contact with the threshold voltage adjusting material. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
Multiple types of gate stacks (100,..., 600) are formed on a doped semiconductor well. A high dielectric constant (high-k) gate dielectric (30L) is formed on the doped semiconductor well (22, 24). A metal gate layer (42L) is formed in one device area, while the high-k gate dielectric is exposed in other device areas (200, 400, 500, 600). Threshold voltage adjustment oxide layers having different thicknesses are formed in the other device areas. A conductive gate material layer (72L) is then formed over the threshold voltage adjustment oxide layers. One type of field effect transistors includes a gate dielectric including a high-k gate dielectric portion. Other types of field effect transistors include a gate dielectric including a high-k gate dielectric portion and a first threshold voltage adjustment oxide portions having different thicknesses. Field effect transistors having different threshold voltages are provided by employing different gate dielectric stacks and doped semiconductor wells having the same dopant concentration.
Abstract:
Multiple types of gate stacks are formed on a doped semiconductor well. A high dielectric constant (high-k) gate dielectric is formed on the doped semiconductor well. A metal gate layer is formed in one device area, while the high-k gate dielectric is exposed in other device areas. Threshold voltage adjustment oxide layers having different thicknesses are formed in the other device areas. A conductive gate material layer is then formed over the threshold voltage adjustment oxide layers. One type of field effect transistors includes a gate dielectric including a high-k gate dielectric portion. Other types of field effect transistors include a gate dielectric including a high-k gate dielectric portion and a first threshold voltage adjustment oxide portions having different thicknesses. Field effect transistors having different threshold voltages are provided by employing different gate dielectric stacks and doped semiconductor wells having the same dopant concentration.