MOSFET having a high stress in the channel region and fabricating method thereof

Abstract

Source and drain extension regions are selectively removed by a dopant concentration dependent etch or a doping type dependent etch, and an embedded stress-generating material such as SiGe alloy or a Si:C alloy in the source and drain extension regions is grown on a semiconductor substrate. The embedded stress-generating material may be grown only in the source and drain extension regions, or in the source and drain extension regions and in deep source and drain regions. In one embodiment, an etch process that removes doped semiconductor regions of one conductivity type selective to doped semiconductor regions of another conductivity type may be employed. In another embodiment, a dopant concentration dependent etch process that removes doped semiconductor regions irrespective of the conductivity type selective to undoped semiconductor regions may be employed.

Description

technical field [0001] (0001) The present invention relates to high performance semiconductor devices for digital or analog applications, and more particularly to complementary metal oxide semiconductor (CMOS) devices with stress-induced mobility enhancement. Specifically, the present invention provides stressed CMOS devices having embedded stress-inducing materials in source and drain extension regions extending from deep source and drain regions toward the channel and methods of manufacturing the same. The direction protrudes laterally, whereby the heterojunction between the two semiconductor materials coincides with the p-n junction, or is located close to the p-n junction. Background technique [0002] (0002) Various techniques for improving the performance of semiconductor devices by controlling carrier mobility have been studied in the semiconductor industry. A key element in this technology classification is the control of stress in the channel of transistor devices....

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Problems solved by technology

Another typical problem of currently known etching techniques is the loading effect, where the etch profile depends on the pattern density, i.e. the local area density of the etchable material

A third typical problem is that the etch profile of an isotropic or anisotropic recess etch can include crystalline facets that form on the surface of the recessed region, which creates challenges for the subsequent epitaxial growth of the embedded material

Further, the reactive ion etching process described above may have a very small process window

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