摘要 |
In advanced SOI devices, a high tensile strain component may be achieved on the basis of a globally strained semiconductor layer, while at the same time a certain compressive strain may be induced in P-channel transistors by appropriately selecting a height-to-length aspect ratio of the corresponding active regions. It has been recognized that the finally obtained strain distribution in the active regions is strongly dependent on the aspect ratio of the active regions. Thus, by selecting a moderately low height-to-length aspect ratio for N-channel transistors, a significant fraction of the initial tensile strain component may be preserved. On the other hand, a moderately high height-to-length aspect ratio for the P-channel transistor may result in a compressive strain component in a central surface region of the active region. |