Semiconductor devices and methods of fabricating the same

Abstract

A method of fabricating a semiconductor device is provided as follows. A source/drain pattern is formed on a substrate. The source/drain pattern contains silicon atoms and germanium atoms. At least one germanium atom is removed from the germanium atoms of the source/drain pattern.

What is claimed is: 
     
         1 . A semiconductor device, comprising:
 active patterns disposed on a substrate, wherein each of the active patterns, extending in a first direction, has a first region and a recessed region;   a device isolation pattern provided on the substrate to cover lower sidewalls of the active patterns;   a gate pattern disposed on the first region of the active pattern, wherein the gate pattern extends in a second direction different from the first direction;   a source/drain pattern disposed on the recessed regions of the active patterns; and   a capping pattern covering the source/drain pattern, wherein the capping pattern has a substantially uniform thickness,   wherein the source/drain pattern comprises:   first portions provided on the recess regions of the active patterns; and   a second portion provided on the device isolation pattern and interposed between the first portions.   
     
     
         2 . The semiconductor device of  claim 1 ,
 wherein the capping pattern comprises a first portion, a second portion connected to the first portion and a third portion connected to the first and second portions, and   the first, second and third portions have substantially a same thickness.   
     
     
         3 . The semiconductor device of  claim 2 ,
 wherein the first portions of source/drain pattern contact the first and second portions of the capping pattern and has a {111} crystal plane, and the second portion of the source/drain pattern contacts the third portion of the capping pattern and has a {100} crystal plane and a {110} crystal plane.   
     
     
         4 . The semiconductor device of  claim 2 ,
 wherein the source/drain pattern and the capping pattern comprise a plurality of germanium atoms, and   the capping pattern has less germanium atoms than the source/drain pattern.   
     
     
         5 . A semiconductor device, comprising:
 an active pattern disposed on a substrate and extended in a first direction;   a gate pattern disposed on a first region of the active pattern and extended in a second direction different from the first direction;   a source/drain pattern disposed on a second region of the active pattern, wherein the second region of the active pattern is adjacent to the gate pattern and the source/drain pattern has a first concentration of germanium atoms;   a first capping pattern covering the source/drain pattern, wherein the first capping pattern has a second concentration of germanium atoms smaller than the first concentration and the capping pattern has a substantially uniform thickness; and   a contact plug penetrating the first capping pattern to be in contact with the source/drain pattern.   
     
     
         6 . The semiconductor device of  claim 5 ,
 wherein a difference between the second concentration and the first concentration is about 3 atomic percent or more.   
     
     
         7 . The semiconductor device of  claim 5 ,
 wherein the second region of the active pattern is recessed, and the source/drain pattern is disposed in the recessed second region.