Tunable gas delivery assembly with internal diffuser and angular injection

Abstract

An apparatus for providing processing gases to a process chamber with improved uniformity is disclosed. One embodiment provides a gas delivery assembly. The gas delivery assembly includes a hub, a nozzle, and one or more gas diffusers disposed in the nozzle. The nozzle has a cylindrical body with a side wall and a top surface. A plurality of injection passages are formed inside the nozzle to deliver processing gases into the process chamber via a plurality of outlets disposed in the side wall. The injection passages are configured to direct process gases out of each outlet disposed in the side wall in a direction which is not radially aligned with a centerline of the hub.

What is claimed is: 
     
         1 . A gas delivery assembly, comprising:
 a cylindrical body having a side wall and a top surface;   a first trench disposed in the top surface, wherein the first trench includes a bottom; and   a first diffuser disposed in the first trench, wherein a first plenum is formed between the first diffuser and the bottom of the first trench.   
     
     
         2 . The gas delivery assembly of  claim 1 , further comprising a second trench disposed in the top surface of the nozzle, wherein the second trench includes a second bottom. 
     
     
         3 . The gas delivery assembly of  claim 2 , further comprising a second diffuser disposed in the second trench, wherein a second plenum is formed between the second diffuser and the bottom of the second trench. 
     
     
         4 . The gas delivery assembly of  claim 3 , further comprising a plurality of outer injection passages formed within the cylindrical body, wherein each of the outer injection passages extends from the bottom of the first trench to a first location inside the cylindrical body that is a first distance away from the top surface. 
     
     
         5 . The gas delivery assembly of  claim 4 , further comprising a plurality of inner injection passages formed within the cylindrical body, wherein each of the inner injection passages extend from the bottom of the second trench to a second location inside the cylindrical body that is a second distance away from the top surface. 
     
     
         6 . The gas delivery assembly of  claim 5 , wherein the second distance is greater than the first distance. 
     
     
         7 . The gas delivery assembly of  claim 5 , further comprising a connecting passage connecting each of the outer injection passages to an outlet disposed in the side wall of the cylindrical body, wherein the connecting passage is substantially parallel to a bottom of the cylindrical body. 
     
     
         8 . The gas delivery assembly of  claim 7 , wherein an angle between the connecting passage and a tangent of the side wall at a corresponding outlet ranges from about 15 degrees to about 60 degrees. 
     
     
         9 . A gas delivery assembly, comprising:
 a hub, comprising:
 an inner channel; and 
 an outer channel; and 
   a nozzle coupled to the hub, wherein the nozzle comprises:
 a cylindrical body having a side wall and a top surface; 
 a first trench disposed in the top surface, wherein the first trench includes a bottom; 
 a second trench disposed in the top surface, wherein the second trench includes a bottom, wherein the inner channel of the hub is aligned with the second trench of the nozzle and the outer channel of the hub is aligned with the first trench of the nozzle; and 
 a first diffuser disposed in the first trench, wherein a first plenum is formed between the first diffuser and the bottom of the first trench. 
   
     
     
         10 . The gas delivery assembly of  claim 9 , further comprising a second diffuser disposed in the second trench, wherein a second plenum is formed between the second diffuser and the bottom of the second trench. 
     
     
         11 . The gas delivery assembly of  claim 10 , further comprising a plurality of outer injection passages formed within the nozzle, wherein each of the outer injection passages extends from the bottom of the first trench to a first location inside the nozzle that is a first distance away from the top surface. 
     
     
         12 . The gas delivery assembly of  claim 11 , further comprising a plurality of inner injection passages formed within the nozzle, wherein each of the inner injection passages extend from the bottom of the second trench to a second location inside the nozzle that is a second distance away from the top surface. 
     
     
         13 . The gas delivery assembly of  claim 12 , wherein the second distance is greater than the first distance. 
     
     
         14 . The gas delivery assembly of  claim 13 , further comprising a connecting passage connecting each of the outer injection passages to an outlet disposed in the side wall of the nozzle, wherein the connecting passage is substantially parallel to a bottom of the nozzle. 
     
     
         15 . The gas delivery assembly of  claim 14 , wherein an angle between the connecting passage and a tangent of the side wall at a corresponding outlet ranges from about 15 degrees to about 60 degrees. 
     
     
         16 . A gas delivery assembly, comprising:
 a nozzle comprising a cylindrical body having a side wall and a top surface;   a first trench disposed in the top surface;   a first diffuser disposed in the first trench, wherein a first plenum is formed between the first diffuser and a bottom of the first trench;   a plurality of outer injection passages formed within the nozzle, wherein each of the outer injection passages extends from the bottom of the first trench to a first location inside the nozzle that is a first distance away from the top surface; and   a connecting passage connecting each of the outer injection passages to a first outlet disposed in the side wall of the nozzle, wherein the connecting passage is substantially parallel to a bottom of the nozzle.   
     
     
         17 . The gas delivery assembly of  claim 16 , further comprising a second trench disposed in the top surface of the nozzle. 
     
     
         18 . The gas delivery assembly of  claim 17 , further comprising a second diffuser disposed in the second trench, wherein a second plenum is formed between the second diffuser and a bottom of the second trench. 
     
     
         19 . The gas delivery assembly of  claim 18 , wherein the first and second diffusers are fabricated from alumina. 
     
     
         20 . The gas delivery assembly of  claim 18 , wherein the first and second diffusers are fabricated from a same material as the nozzle.