Gas Distribution System for Improved Transient Phase Deposition

Abstract

Embodiments of the present invention are directed to a gas distribution system which distributes the gas more uniformly into a process chamber. In one embodiment, a gas distribution system comprises a gas ring including an outer surface and an inner surface, and a gas inlet disposed at the outer surface of the gas ring. The gas inlet is fluidicly coupled with a first channel which is disposed between the outer surface and the inner surface of the gas ring. A plurality of gas outlets are distributed over the inner surface of the gas ring, and are fluidicly coupled with a second channel which is disposed between the outer surface and the inner surface of the gas ring. A plurality of orifices are fluidicly coupled between the first channel and the second channel. The plurality of orifices are spaced from the gas inlet by a plurality of distances, and have sizes which vary with the distances from the gas inlet as measured along the first channel, such that the size of the orifice increases with an increase in the distance between the orifice and the gas inlet as measured along the first channel.

1 . A method of distributing a gas flowing into a chamber for processing a substrate, the method comprising: 
 providing a gas ring including an outer surface and an inner surface, a first channel disposed between the outer surface and the inner surface, and a second channel disposed between the outer surface and the inner surface, the first channel being fluidicly coupled with the second channel via a plurality of orifices; and    introducing a gas into the gas ring via a gas inlet disposed at the outer surface of the gas ring, the gas flowing via the gas inlet into the first channel through the plurality of orifices into the second channel and through a plurality of gas outlets which are fluidicly coupled with the second channel, and into the chamber;    wherein the plurality of orifices are spaced from the gas inlet by a plurality of distances, wherein the orifices have different sizes to provide a substantially uniform distribution of the gas into the chamber via the gas outlets during a transient period when the gas is initially introduced into the gas ring.    
   
   
       2 . The method of claim  13  wherein the sizes of the openings vary with the distances from the gas inlet as measured along the first channel, such that the size of the opening increases with an increase in the distance between the opening and the gas inlet as measured along the first channel.  
   
   
       3 . The method of claim  13  wherein the plurality of orifices are substantially symmetrically disposed with respect to a line passing through the gas inlet and a center of a circumference of the first channel.  
   
   
       4 . The method of claim  13  wherein the plurality of orifices comprise an even number of orifices which is greater than two, and wherein none of the orifices lie on the line passing through the gas inlet and the center of the circumference of the first channel.  
   
   
       5 . The method of claim  13  wherein the plurality of orifices are substantially uniformly spaced along the circumference of the first channel.  
   
   
       6 . The method of claim  13  wherein the gas comprises a silicon-source gas.  
   
   
       7 . The method of claim  13  wherein the gas is reacted inside the chamber to form a lining layer on the substrate.  
   
   
       8 . The method of claim  13  wherein the gas is reacted inside the chamber by applying a plasma in the chamber.