Semiconductor devices having faceted silicide contacts, and related fabrication methods
View Patent ↗The disclosed subject matter relates to semiconductor transistor devices and associated fabrication techniques that can be utilized to form silicide contacts having an increased effective size, relative to conventional silicide contacts. A semiconductor device fabricated in accordance with the processes disclosed herein includes a layer of semiconductor material and a gate structure overlying the layer of semiconductor material. A channel region is formed in the layer of semiconductor material, the channel region underlying the gate structure. The semiconductor device also includes source and drain regions in the layer of semiconductor material, wherein the channel region is located between the source and drain regions. Moreover, the semiconductor device includes facet-shaped silicide contact areas overlying the source and drain regions.
1. A method of fabricating a semiconductor device, the method comprising:
providing a substrate having a layer of semiconductor material;
creating a gate structure overlying the layer of semiconductor material;
forming recesses in the layer of semiconductor material adjacent to the gate structure; and
at least partially filling the recesses with a filler semiconductor material, to form facet-shaped semiconductor regions in the recesses; wherein:
at least partially filling the recesses comprises epitaxially growing the filler semiconductor material in the recesses under growth conditions that promote formation of the facet-shaped semiconductor regions;
forming recesses in the layer of semiconductor material results in exposed recess surfaces that correspond to the {110} plane of the semiconductor material;
epitaxially growing the filler semiconductor material is performed under growth conditions that promote a relatively high growth rate of the filler semiconductor material for its {111} planes, and a relatively low growth rate of the filler semiconductor material for its {110} plane; and
the facet-shaped semiconductor regions comprise facet regions that point downward, relative to the substrate.
2. The method of claim 1 , wherein epitaxially growing the filler semiconductor material is performed at a relatively low growth temperature.
3. The method of claim 2 , wherein epitaxially growing the filler semiconductor material is performed at a growth temperature within the range of about 500-580 degrees Celsius.
4. The method of claim 1 , wherein at least partially filling the recesses comprises epitaxially growing in situ doped semiconductor material in the recesses.
5. The method of claim 1 , wherein at least partially filling the recesses comprises at least partially filling the recesses with a stress-inducing semiconductor material.