Apparatus and method for wafer pre-wetting

Abstract

A semiconductor apparatus includes a process chamber, a workpiece holder and a pre-wetting fluid tank. The workpiece holder is disposed within the process chamber to hold a semiconductor workpiece. The pre-wetting fluid tank is disposed outside the process chamber, wherein the workpiece holder comprises an inner sidewall, an outer sidewall and a channel between the inner sidewall and the outer sidewall, the channel is coupled to the pre-wetting fluid tank, and the outer sidewall is higher than the inner sidewall relative to a major surface of the semiconductor workpiece.

What is claimed is: 
     
         1 . A semiconductor apparatus, comprising:
 a process chamber;   a workpiece holder disposed within the process chamber to hold a semiconductor workpiece; and   a pre-wetting fluid tank disposed outside the process chamber, wherein the workpiece holder comprises an inner sidewall, an outer sidewall and a channel between the inner sidewall and the outer sidewall, the channel is coupled to the pre-wetting fluid tank, and the outer sidewall is higher than the inner sidewall relative to a major surface of the semiconductor workpiece.   
     
     
         2 . The semiconductor apparatus of  claim 1 , wherein an outlet of the channel is separated from the semiconductor workpiece by the inner sidewall. 
     
     
         3 . The semiconductor apparatus of  claim 1 , wherein an outlet of the channel is formed between an inclined top surface of the inner sidewall and an inclined top surface of the outer sidewall. 
     
     
         4 . The semiconductor apparatus of  claim 3 , wherein the inclined top surfaces of the inner sidewall and the outer sidewall face an axis penetrating through a center of the semiconductor workpiece. 
     
     
         5 . The semiconductor apparatus of  claim 1 , wherein the channel is configured to deliver a pre-wetting fluid from the pre-wetting fluid tank out through an outlet of the channel to wet the major surface of the semiconductor workpiece. 
     
     
         6 . The semiconductor apparatus of  claim 5 , further comprising:
 a heating device coupled to the pre-wetting fluid tank to cause vaporization of the pre-wetting fluid.   
     
     
         7 . The semiconductor apparatus of  claim 6 , wherein the channel is coupled to the heating device to maintain at a temperature for delivering the pre-wetting fluid in vapor form. 
     
     
         8 . The semiconductor apparatus of  claim 5 , further comprising:
 a temperature control device coupled to the workpiece holder to reduce a temperature of the semiconductor workpiece lower than a dew point temperature of the pre-wetting fluid.   
     
     
         9 . A semiconductor apparatus, comprising:
 a process chamber;   a workpiece holder disposed within the process chamber, comprising an inner sidewall and an outer sidewall, wherein the inner sidewall forms a space to hold a semiconductor workpiece;   a pre-wetting fluid tank disposed outside the process chamber and containing a pre-wetting fluid; and   a conduit, coupled to the pre-wetting fluid tank to deliver the pre-wetting fluid, wherein the conduit is disposed between the inner sidewall and the outer sidewall, the outer sidewall is higher than the inner sidewall relative to a major surface of the semiconductor workpiece, and an excess portion of the pre-wetting fluid overflows from the outer sidewall of the workpiece holder.   
     
     
         10 . The semiconductor apparatus of  claim 9 , wherein the conduit is configured to deliver the pre-wetting fluid tank out through an outlet of the conduit to wet a major surface of the semiconductor workpiece. 
     
     
         11 . The semiconductor apparatus of  claim 10 , wherein the outlet of the conduit is an annular trench encircling a periphery of the semiconductor workpiece in a top view. 
     
     
         12 . The semiconductor apparatus of  claim 9 , wherein the major surface of the semiconductor workpiece comprises a plurality of recess portions. 
     
     
         13 . The semiconductor apparatus of  claim 9 , further comprising:
 a moving mechanism coupled to and disposed below the workpiece holder, wherein the semiconductor workpiece is driven by the moving mechanism to rotate about an axis that passes through a center of the semiconductor workpiece and is perpendicular to the major surface of the semiconductor workpiece.   
     
     
         14 . The semiconductor apparatus of  claim 9 , wherein the conduit comprises:
 a first channel in fluidic communication with the pre-wetting fluid tank, extending in a first direction inside the workpiece holder, and disposed below the major surface of the semiconductor workpiece; and   a second channel in fluidic communication with the first channel, extending in a second direction inside the workpiece holder, and disposed in proximity to a sidewall of the semiconductor workpiece.   
     
     
         15 . The semiconductor apparatus of  claim 9 , wherein a first shortest distance between a top of the outer sidewall of the workpiece holder and a reference plane where the major surface of the semiconductor workpiece is located on is greater than a second shortest distance between a top of the inner sidewall and the reference plane where the major surface of the semiconductor workpiece is located on. 
     
     
         16 . A method, comprising:
 placing a semiconductor workpiece on a workpiece holder in a process chamber, wherein the workpiece holder comprises an inner sidewall, an outer sidewall and a conduit between the inner sidewall and the outer sidewall, and the outer sidewall is higher than the inner sidewall relative to a major surface of the semiconductor workpiece;   pre-wetting the semiconductor workpiece comprising:
 decreasing a pressure in the process chamber; 
 flowing a pre-wetting fluid to the semiconductor workpiece through the conduit to wet the major surface of the semiconductor workpiece; and 
 increasing the pressure in the process chamber; 
   removing the pre-wetting fluid from the semiconductor workpiece; and   plating a conductive material on the semiconductor workpiece.   
     
     
         17 . The method of  claim 16 , wherein flowing the pre-wetting fluid to the semiconductor workpiece comprises:
 flowing the pre-wetting fluid through the conduit; and   overflowing the pre-wetting fluid from the inner sidewall of the workpiece holder to the major surface of the semiconductor workpiece.   
     
     
         18 . The method of  claim 17 , wherein pre-wetting the semiconductor workpiece further comprises:
 overflowing an excess portion of the pre-wetting fluid from the outer sidewall of the workpiece holder; and   discharging the excess portion of the pre-wetting fluid.   
     
     
         19 . The method of  claim 17 , wherein flowing the pre-wetting fluid inside the workpiece holder comprises:
 flowing the pre-wetting fluid upwardly from a pre-wetting fluid tank through a first channel of the conduit;   flowing the pre-wetting fluid horizontally through a second channel of the conduit, wherein the second channel is connected to the first channel and embedded in the workpiece holder; and   flowing the pre-wetting fluid upwardly through a third channel of the conduit, wherein the third channel is connected to the second channel and embedded in the workpiece holder.   
     
     
         20 . The method of  claim 16 , wherein a fluid pressure of the pre-wetting fluid flowing to the semiconductor workpiece is regulated in range of 10 psi and about 100 psi.