Method and apparatus for deposition of low dielectric constant materials

Abstract

A showerhead adapted for distributing gases into a process chamber and a method for forming dielectric layers on a substrate are generally provided. In one embodiment, a showerhead for distributing gases in a processing chamber includes an annular body coupled between a disk and a mounting flange. The disk has a plurality of holes formed therethrough. A lip extends from a side of the disk opposite the annular body and away from the mounting flange. The showerhead may be used for the deposition of dielectric materials on a substrate. In one embodiment, silicon nitride and silicon oxide layers are formed on the substrate without removing the substrate from a processing chamber utilizing the showerhead of the present invention.

1 . A processing chamber comprising: 
 a chamber body;    a lid disposed on the chamber body and enclosing an interior volume of the chamber body;    a substrate support disposed in the chamber body and having a heating element disposed therein;    a face plate having a plurality of holes formed therethrough, each hole including a restrictive section, a center passage section, and an opening section;    an annular body having a first end coupled to a first side of the face plate;    a mounting flange coupled to a second end of the annular body and coupled to the lid; and    an annular lip extending from a second side of the face plate opposite the mounting flange and defining a peripheral boundary to a plasma containing region, the lip having an inner diameter less than a diameter of the substrate support and an outer diameter greater than the diameter of the substrate support.    
   
   
       2 . The chamber of  claim 1 , wherein the inner diameter of the lip is less than a diameter of the heating element.  
   
   
       3 . The chamber of  claim 1 , wherein the holes have a conical portion tapering toward the second side of the face plate.  
   
   
       4 . The chamber of  claim 1 , wherein the holes are arranged on a bolt circle of about 8.695 to about 8.705 inches.  
   
   
       5 . The chamber of  claim 1 , wherein the face plate has a diameter of about 9.75 inches.  
   
   
       6 . The chamber of  claim 1 , wherein the lip defines an angle of between about 80 and about 90 degrees relative to the face plate.  
   
   
       7 . The chamber of  claim 1 , wherein the lip is perpendicular to the face plate.  
   
   
       8 . A method for depositing dielectric layers on a substrate, the method comprising: 
 transferring the substrate into a chemical vapor deposition chamber;    forming a layer of silicon nitride on the substrate; and    forming a layer of silicon oxide on the substrate without removing the substrate from the chamber.    
   
   
       9 . The method of  claim 8 , wherein the forming a layer of silicon nitride comprises flowing at least one process gas selected from the group consisting of SiH 4  (silane), tetramethyl silane, and trimethyl silane and a nitrogen comprising gas through a showerhead of the chemical vapor deposition chamber and into the chemical vapor deposition chamber.  
   
   
       10 . The method of  claim 8 , wherein the forming a layer of silicon nitride comprises applying a bias between a showerhead of the chemical vapor deposition chamber and the substrate.  
   
   
       11 . The method of  claim 10 , wherein the forming a layer of silicon nitride further comprises positioning the substrate in the chamber to define a spacing of about 200 to about 900 mils relative to the showerhead.  
   
   
       12 . The method of  claim 8 , wherein the forming a layer of silicon oxide on the substrate comprises flowing at least one process gas selected from the group consisting of tetraethyl oxysilane (TEOS), tetramethyl silane, trimethyl silane (TMS), and silane and an oxygen containing gas through a showerhead of the chemical vapor deposition chamber and into the chemical vapor deposition chamber.  
   
   
       13 . The method of  claim 8 , wherein the forming a layer of silicon oxide on the substrate comprises applying a bias voltage to a showerhead of the chemical vapor deposition chamber.  
   
   
       14 . The method of  claim 13 , wherein the forming a layer of silicon oxide on the substrate further comprises positioning the substrate in the chamber to define a spacing of about 300 to about 1000 mils relative to the showerhead.  
   
   
       15 . The method of  claim 8 , wherein a process kit of the chemical vapor deposition chamber is not changed between the forming a layer of silicon nitride and the forming a layer of silicon oxide.  
   
   
       16 . The method of  claim 8 , further comprising helium plasma treating the silicon oxide layer.  
   
   
       17 . A method for depositing dielectric layers on a substrate, the method comprising: 
 a) transferring the substrate into a chemical vapor deposition chamber;    b) forming a layer of silicon nitride by a process comprising: 
 positioning the substrate in the chamber to define a spacing of about 200 to about 900 mils relative to a showerhead in the chamber;  
 heating the substrate to about 300 to about 400 degrees Celsius;  
 flowing at least one process gas selected from the group consisting of SiH 4  (silane), tetramethyl silane and trimethyl silane at a rate of about 100 to about 200 sccm through the showerhead and into the chamber;  
 flowing a nitrogen comprising gas at a rate of about 200 to about 400 sccm through the showerhead and into the chamber; and  
 applying a bias between the showerhead and the substrate of about 200 to about 500 Watts; and  
   c) forming a layer of silicon oxide on the substrate without removing the substrate from the chamber by a process comprising: 
 positioning the substrate in the chamber to define a spacing of about 300 to about 1000 mils relative to the showerhead;  
 heating the substrate to about 300 to about 400 degrees Celsius;  
 applying a bias voltage of about 525 to about 850 Watts to the showerhead;  
 flowing at least one process gas selected from the group consisting of tetraethyl oxysilane (TEOS), tetramethyl silane, trimethyl silane (TMS), and silane at a rate of about 1000 to about 1400 sccm through the showerhead and into the chamber; and  
 flowing an oxygen containing gas at a rate of about 350 to about 450 sccm through the showerhead and into the chamber.  
   
   
   
       18 . The method of  claim 17 , wherein the forming the layer of silicon nitride further comprises: 
 flowing an inert gas through the showerhead at a rate of about 200 to about 800 sccm.    
   
   
       19 . The method of  claim 17 , wherein the forming the layer of silicon oxide further comprises: 
 maintaining the chamber pressure at about 5 Torr or greater.    
   
   
       20 . The method of  claim 17 , wherein the forming the layer of silicon oxide further comprises: 
 flowing an inert gas through the showerhead at a rate of about 400 to about 800 sccm.