| 摘要 |
Multiple gate transistors are provided with a dual stress layer for increased channel mobility and enhanced effective and saturated drive currents. Embodiments include transistors comprising a first stress layer under the bottom gate and a second stress layer overlying the top gate. Embodiments further include transistors with the bottom gate within or through the first stress layer. Methodology includes sequentially depositing stressed silicon nitride, nitride, oxide, amorphous silicon, and oxide layers on a substrate having a bottom oxide layer thereon, patterning to define a channel length, depositing a top nitride layer, patterning stopping on the stressed silicon nitride layer, removing the amorphous silicon layer, epitaxially growing silicon through a window in the substrate to form source, drain, and channel regions, doping, removing the deposited nitride and oxide layers, growing gate oxides, depositing polysilicon to form gates, growing isolation oxides, and depositing the top stress layer.
|
