Low-temperature selective epitaxial growth of silicon for device integration

Abstract

An epitaxy method includes providing an exposed crystalline region of a substrate material. Silicon is epitaxially deposited on the substrate material in a low temperature process wherein a deposition temperature is less than 500 degrees Celsius. A source gas is diluted with a dilution gas with a gas ratio of dilution gas to source gas of less than 1000.

What is claimed is: 
     
         1 . An epitaxy method, comprising:
 providing a crystalline substrate material;   growing an insulator on the substrate material;   opening the insulator to form exposed areas of the substrate material;   depositing silicon on the exposed areas of the substrate material to form epitaxial silicon on the exposed areas and form non-epitaxial silicon in other than the exposed areas in a low temperature process wherein a deposition temperature is less than 500 degrees Celsius; and   etching the non-epitaxial silicon using a plasma to further epitaxial deposition of silicon over the exposed areas.   
     
     
         2 . The method as recited in  claim 1 , wherein depositing silicon includes a radio frequency or direct current plasma enhanced chemical vapor deposition process. 
     
     
         3 . The method as recited in  claim 1 , wherein depositing silicon includes diluting a source gas with a dilution gas including at least one of H 2 , HCl, Cl 2  and Ar with a gas ratio of dilution gas to source gas of less than 1000, wherein the source gas includes one of SiH 4 , dichlorosilane (DCS), SiF 4  or SiCl 4 . 
     
     
         4 . The method as recited in  claim 3 , wherein diluting include diluting SiH 4  with at least one of H 2  with a gas ratio of over 5. 
     
     
         5 . The method as recited in  claim 1 , wherein the deposition temperature is less than 250 degrees Celsius. 
     
     
         6 . The method as recited in  claim 1 , wherein the substrate material includes one of Si, Ge, and III-V materials. 
     
     
         7 . The method as recited in  claim 1 , further comprising introducing a dopant with a gas ratio which provides a doped epitaxial silicon. 
     
     
         8 . The method as recited in  claim 7 , wherein the doped epitaxial silicon includes at least one of carbon, germanium, phosphorus, arsenic or boron. 
     
     
         9 . The method as recited in  claim 1 , wherein the plasma includes at least one of H 2 , HCl, Cl 2  or Ar. 
     
     
         10 . The method as recited in  claim 1 , wherein selective epitaxial growth is provided by alternating the depositing and etching steps. 
     
     
         11 . The method as recited in  claim 1 , wherein the steps of depositing and etching are concurrently performed.