Disposable spacer

Abstract

A disposable spacer for use in a semiconductor device fabrication process is formed of a germanium-silicon alloy. The germanium-silicon alloy may include a first portion (x) of germanium and a second portion ( 1 -x) of silicon, wherein x is greater than about 0.2. A method of forming the disposal spacer includes providing a device structure and forming a layer of germanium-silicon alloy on the device structure. The layer is then etched to form the disposable spacer. The device structure may include a substrate and a gate structure with the disposable spacers formed at sidewalls thereof. Further, the device structure may include a substrate having an oxidation mask formed thereon with the disposable spacers formed relative to sidewalls of the oxidation mask. In addition, the method includes removing the disposable spacer by oxidizing the spacer to form volatile Ge x Si y O. Any unvolatilized Ge x Si y O may be removed using water. Further, the removal step may be performed using a cleaning solution including ammonium hydroxide.

1 - 42 . (canceled)  
   
   
       43 . A disposable spacer for use in a semiconductor device fabrication process, the spacer comprising a germanium-silicon alloy, wherein the germanium-silicon alloy includes a first portion (x) of germanium and a second portion ( 1 -x) of silicon, wherein x is greater than about 0.7.  
   
   
       44 . The spacer according to  claim 43 , wherein the disposable spacer is formed upon sidewalls of a gate structure.  
   
   
       45 . The spacer according to  claim 43 , wherein the disposable spacer is formed relative to sidewalls of an oxidation mask.  
   
   
       46 . The spacer according to  claim 43 , wherein x is greater than 0.9.  
   
   
       47 . A disposable spacer for use in a semiconductor device fabrication process, the spacer comprising a germanium-silicon alloy, wherein the germanium-silicon alloy includes a first portion (x) of germanium and a second portion ( 1 -x) of silicon, wherein x is greater than about 0.7, wherein permanent spacers are formed upon sidewalls of a gate structure, and further wherein the disposable spacer is formed upon at least one of the permanent spacers.  
   
   
       48 . The spacer according to  claim 47 , wherein x is greater than 0.9.  
   
   
       49 . A disposable spacer for use in a semiconductor device fabrication process, the spacer comprising a germanium-silicon alloy, wherein the germanium-silicon alloy includes a first portion (x) of germanium and a second portion ( 1 -x) of silicon, wherein x is greater than about 0.7, and further wherein the disposable spacer is removable by oxidation followed by a water rinse.  
   
   
       50 . The spacer according to  claim 49 , wherein the disposable spacer is formed upon sidewalls of a gate structure.  
   
   
       51 . The spacer according to  claim 49 , wherein the disposable spacer is formed relative to sidewalls of a oxidation mask.  
   
   
       52 . The spacer according to  claim 49 , wherein x is greater than 0.9.