SiGe FINS FORMED ON A SUBSTRATE

Abstract

A semiconductor structure includes at least one silicon-germanium (SiGe) fin with a first width. The semiconductor structure includes at least one silicon (Si) fin with a second width. An oxide layer isolates the at least one SiGe fin with the first width from a substrate. The at least one SiGe fin with the first width, the at least one Si fin with the second width and a surface of the substrate below the at least one Si fin are each oxidized.

What is claimed is: 
     
         1 . A semiconductor structure, comprising:
 at least one silicon-germanium (SiGe) fin with a first width;   at least one silicon (Si) fin with a second width;   an oxide layer isolating the at least one SiGe fin with the first width from a substrate, wherein the at least one SiGe fin with the first width, the at least one Si fin with the second width and a surface of the substrate below the at least one Si fin are each oxidized.   
     
     
         2 . The semiconductor structure of  claim 1 , wherein the oxide layer is formed based on oxidizing a top surface of the substrate, the SiGe fin with the first width and the Si fin with the second width. 
     
     
         3 . The semiconductor structure of  claim 2 , wherein the Si fin with the second width is formed based on etching the Si fin with the second width from the substrate. 
     
     
         4 . The semiconductor structure of  claim 3 , wherein the SiGe fin with a first width is formed based on etching the at least one SiGe fin with the first width from an SiGe layer. 
     
     
         5 . The semiconductor structure of  claim 4 , wherein the SiGe layer resides on the substrate. 
     
     
         6 . The semiconductor structure of  claim 5 , wherein a height of the at least one SiGe fin with the first width is reduced after oxidizing and the first width is reduced after oxidizing. 
     
     
         7 . The semiconductor structure of  claim 6 , wherein a percentage of Ge in the at least one SiGe fin with the reduced first width is greater than a percentage of Ge in the SiGe layer. 
     
     
         8 . The semiconductor structure of  claim 2 , wherein the first width of the at least one SiGe fin is greater than the second width of the at least one Si fin. 
     
     
         9 . The semiconductor structure of  claim 2 , wherein a portion of Si from the at least one SiGe fin with the first width and the at least one Si fin with the second width as a result of forming the oxide layer. 
     
     
         10 . A method, comprising:
 selectively forming a silicon-germanium (SiGe) layer on a substrate by epitaxially growing the SiGe layer on a top surface of the substrate;   forming at least one fin with a first width from the SiGe layer by forming a masking layer on the top surface of the SiGe layer, etching the at least one fin with the first width, and forming a spacer layer on the at least one fin with the first width;   forming at least one other fin with a second width from the substrate by etching the substrate to form the at least one other fin with the second width, wherein the second width is less than the first width, and selectively removing the spacer layer from the at least one fin with the first width; and   oxidizing the at least one fin with the first width, the at least one other fin with the second width and a surface of the substrate below the at least one other fin with the second width, wherein the first width is condensed in width to a target width, the at least one other fin is completely oxidized forming an oxide layer between the at least one fin with the first width and the substrate.   
     
     
         11 . The method of  claim 10 , wherein oxidizing the at least one other fin with the second width creates the oxide layer that isolates the at least one fin with the first width from the substrate;
 a height of the at least one fin with the first width is reduced after oxidizing;   the first width is reduced after oxidizing; and   a percentage of Ge in the at least one fin with the reduced first width is greater than a percentage of Ge in the SiGe layer.