| CPC H01L 29/785 (2013.01) [H01L 21/02433 (2013.01); H01L 21/0262 (2013.01); H01L 21/823814 (2013.01); H01L 29/045 (2013.01); H01L 29/0847 (2013.01); H01L 29/1037 (2013.01); H01L 29/66545 (2013.01); H01L 29/66795 (2013.01); H01L 29/7848 (2013.01); H01L 21/3065 (2013.01); H01L 27/0924 (2013.01)] | 20 Claims |
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1. A method comprising:
forming a plurality of fins protruding from a semiconductor substrate;
forming an isolation region surrounding the plurality of fins;
forming a gate structure over the plurality of fins; and
forming an epitaxial source/drain region adjacent the gate structure and extending over the plurality of fins, comprising:
performing a first deposition process to deposit a first epitaxial material on the plurality of fins, wherein bottom surfaces of the first epitaxial material on adjacent fins merge at a first height above the isolation region;
performing an etching process on the first epitaxial material, wherein the etching process etches bottom surfaces of the first epitaxial material; and
after performing the etching process, performing a second deposition process to deposit a second epitaxial material on the first epitaxial material, the epitaxial source/drain region comprising the first epitaxial material and the second epitaxial material, wherein after performing the second deposition process, bottom surfaces of the epitaxial source/drain region between adjacent fins extend a second height above the isolation region that is greater than the first height.
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9. A method comprising:
forming a first fin and a second fin protruding from a semiconductor substrate;
performing a first epitaxial growth process to form a first epitaxial region on the first fin and a second epitaxial region on the second fin, wherein the upper surfaces and lower surfaces of the first epitaxial region and the second epitaxial region are {111} facets, wherein middle surfaces of the first epitaxial region and the second epitaxial region that are between the upper surfaces and the lower surfaces comprise {110} facets;
performing an anisotropic etching process to preferentially etch the {110} facets of the first epitaxial region and the second epitaxial region; and
performing a second epitaxial growth process to form a third epitaxial region on the first epitaxial region and the second epitaxial region, wherein the third epitaxial region continuously extends from the first epitaxial region to the second epitaxial region.
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16. A method comprising:
forming a first fin and a second fin on a substrate;
forming a first epitaxial source/drain region on the first fin;
forming a second epitaxial source/drain region on the second fin, wherein the first epitaxial source/drain region and the second epitaxial source/drain region merge at a first height above the substrate;
etching upper surfaces and side surfaces of the first epitaxial source/drain region and the second epitaxial source/drain region using an etching process; and
depositing an epitaxial material on the first epitaxial source/drain region and the second epitaxial source/drain region to form an epitaxial structure comprising the first epitaxial source/drain region, the second epitaxial source/drain region, and the epitaxial material, wherein a bottom surface of the epitaxial structure has a slope turning point that is a second height above the substrate less than the first height, wherein the bottom surface has a first slope below the slope turning point and a second slope above the slope turning point that is greater than the first slope.
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