Gas delivery system for semiconductor processing

Abstract

A replaceable gas nozzle is insertable in a gas distributor ring of a substrate processing chamber and that can be shielded within the chamber. The replaceable gas nozzle has a longitudinal ceramic body having a channel to direct the flow of the gas into the chamber. The ceramic body includes a first external thread to mate with the gas distributor ring, and a second external thread to receive a heat shield. The channel has an inlet to receive the gas from the gas distributor ring and a pinhole outlet to release the gas into the chamber. A heat shield can be used to shield the nozzle extending into the chamber. The heat shield has a hollow member configured to be coupled with the nozzle that has an internal dimension sufficiently large to be disposed around at least a portion of the nozzle. The hollow member also has an extension which projects distally of the outlet of the nozzle and a heat shield opening for the process gas to flow therethrough from the nozzle outlet.

What is claimed is:  
     
         1 . A replaceable gas nozzle that is insertable in a gas distributor ring of a substrate processing chamber and that can be shielded within the chamber, the gas nozzle comprising: 
 a longitudinal ceramic body having a channel to direct the flow of the gas into the chamber, the ceramic body comprising a first external thread to mate with the gas distributor ring, a second external thread to receive a heat shield, the channel comprising an inlet to receive the gas from the gas distributor ring, and a pinhole outlet at the end of the channel to release the gas into the chamber.    
     
     
         2 . A nozzle according to  claim 1  wherein the pinhole outlet has a diameter d o , and wherein the distance d st  between the second external thread and the pinhole outlet is about 90 d o  to about 140 d o .  
     
     
         3 . A nozzle according to  claim 2  wherein d o  is from about 0.3 mm to about 0.4 mm.  
     
     
         4 . A nozzle according to  claim 2  wherein d st  is from about 30 mm to about 55 mm.  
     
     
         5 . A nozzle according to  claim 1  wherein the ceramic body is composed of aluminum oxide.  
     
     
         6 . A nozzle according to  claim 1  wherein the ceramic body is composed of aluminum nitride.  
     
     
         7 . A nozzle according to  claim 1  wherein the ceramic body tapers at an angle from about 35 to about 45° to the pinhole outlet.  
     
     
         8 . A nozzle according to  claim 1  further comprising a heat shield mounted on the second external thread.  
     
     
         9 . A heat shield for shielding a nozzle extending into a chamber to introduce a process gas into the chamber through a nozzle outlet, wherein the chamber defines a processing region therein and has a substrate support to support a substrate for processing in the chamber, the heat shield comprising: 
 a hollow member configured to be coupled with the nozzle and having an internal dimension sufficiently large to be disposed around at least a portion of the nozzle, the hollow member having an extension which projects distally of the nozzle outlet and which includes a heat shield opening for the process gas to flow therethrough from the nozzle outlet.    
     
     
         10 . The heat shield of  claim 3  wherein the hollow member is cylindrical and has an internal cross-section which is larger than an external cross-section of the nozzle by about an amount smaller than the thickness of the heat shield.  
     
     
         11 . The heat shield of  claim 3  wherein the hollow member comprises a ceramic material.  
     
     
         12 . The heat shield of  claim 3  wherein the extension of the heat shield is sized to project distally of the nozzle outlet by a distance of between about a radius of the nozzle and about a diameter of the nozzle.  
     
     
         13 . A heat shield according to  claim 5  wherein the ceramic material comprises aluminum oxide or aluminum nitride.  
     
     
         14 . A heat shield according to  claim 6  wherein the extension projects distally by about 5 mm to about 8 mm.  
     
     
         15 . A shielded gas nozzle for a substrate processing chamber comprising: 
 (a) a longitudinal ceramic body having a channel to direct the flow of the gas into the chamber, the ceramic body comprising a first external thread to mate with the gas distributor ring, a second external thread to receive a heat shield, the channel comprising an inlet to receive the gas from the gas distributor ring, and a pinhole outlet at the end of the channel to release the gas into the chamber.    (b) a hollow member configured to be coupled with the ceramic body and having an internal dimension sufficiently large to be disposed around at least a portion of the ceramic body, the hollow member having an extension which projects distally of the pinhole outlet and which includes a heat shield opening for the process gas to flow therethrough from the pinhole outlet.    
     
     
         16 . A nozzle according to  claim 1  wherein the pinhole outlet has a diameter d o , and wherein the distance d st  between the second external thread and the pinhole outlet is about 90 d o  to about 140 d o .  
     
     
         17 . The heat shield of  claim 3  wherein the hollow member is cylindrical and has an internal cross-section which is larger than an external cross-section of the ceramic body by about an amount smaller than the thickness of the hollow member.  
     
     
         18 . The heat shield of  claim 3  wherein the extension of the hollow member is sized to project distally of the pinhole outlet by a distance of between about a radius of the ceramic body and about a diameter of the ceramic body.  
     
     
         19 . A shielded gas nozzle according to  claim 1  wherein the ceramic body and hollow member are composed of aluminum oxide.  
     
     
         20 . A shielded gas nozzle according to  claim 1  wherein the ceramic body and the hollow member are composed of aluminum nitride.