Methods of electrochemical plating

Abstract

An electrochemical plating apparatus for depositing a conductive material on a wafer includes a cell chamber. The plating solution is provided from a bottom of the cell chamber into the cell chamber. A plurality of openings passes through a sidewall of the cell chamber. A flow regulator is arranged with each of the plurality of openings configured to regulate an overflow amount of the plating solution flowing out through the each of the plurality of openings. The electrochemical plating apparatus further comprises a controller to control the flow regulator such that overflow amounts of the plating solution flowing out through the plurality of openings are substantially equal to each other.

What is claimed is: 
     
         1 . An electrochemical plating method, the method comprising:
 providing a plating solution from a bottom of a cell chamber, wherein a plurality of openings pass through a sidewall of the cell chamber and a plurality of flow regulators are provided such that a flow regulator of the plurality of flow regulators is arranged with each opening of the plurality of openings;   measuring flow rates of the plating solution flowing through the flow regulator of each opening of the plurality of openings;   calculating, by a feedback controller, a differential flow rate of the plating solution;   determining whether the differential flow rate of the plating solution is within an acceptable range; and   in response to a determination that the differential flow rate is not within the acceptable range, automatically adjusting a configurable parameter of at least one flow regulator of the plurality of flow regulators to set the differential flow rate within the acceptable range.   
     
     
         2 . The method of  claim 1 , wherein automatically adjusting the configurable parameter of the at least one flow regulator further comprises:
 adjusting an adjustable slit of the at least one flow regulator.   
     
     
         3 . The method of  claim 2 , further comprising, before measuring the flow rates of the plating solution:
 rotating a wafer to be plated in the cell chamber to cause a rotating movement of the plating solution.   
     
     
         4 . The method of  claim 2 , wherein the differential flow rate comprises one or more differences between flow rates of the plating solution flowing through flow regulators of the plurality of flow regulators arranged with one or more pairs of the plurality of openings, and the method further comprises generating, by the feedback controller, a notification based on a determination indicating the differential flow rate is within the acceptable range. 
     
     
         5 . The method of  claim 1 , wherein, in response to a determination that the differential flow rate is within the acceptable range, repeating the measuring the flow rates of the plating solution, the calculating of the differential flow rate of the plating solution, and the determining whether the differential flow rate of the plating solution is within an acceptable range. 
     
     
         6 . The method of  claim 1 , further comprising recirculating the plating solution that has flowed through the flow regulator of each opening of the plurality of openings to the bottom of the cell chamber. 
     
     
         7 . The method of  claim 6 , further comprising storing the plating solution that has flowed through the flow regulator of each opening of the plurality of openings before recirculating the plating solution to the bottom of the cell chamber. 
     
     
         8 . A method of electrochemical plating on a wafer, the method comprising:
 providing a plating solution through an entry port of a cell chamber into the cell chamber;   directing the plating solution, entering from the entry port, towards a surface of the wafer;   flowing the plating solution through first and second openings in a sidewall of the cell chamber out of the cell chamber;   regulating flow of the plating solution through the first and second openings;   determining whether a differential flow rate between flow rates of the plating solution through the first and second openings is within an acceptable range; and   in response to a determination that the differential flow rate is outside the acceptable range, adjusting the flow rate of the plating solution through at least one of the first and second openings.   
     
     
         9 . The method of  claim 8 , wherein the cell chamber has a cylindrical shape and the first and second openings are arranged in a plane perpendicular to a center axis of the cell chamber. 
     
     
         10 . The method of  claim 8 , wherein a flow regulator is arranged with each of the first and second openings, and wherein the flow regulator adjusts the flow rates of the plating solution through the first and second openings. 
     
     
         11 . The method of  claim 10 , wherein the flow regulator of each one of the first and second openings includes an adjustable slit through which the plating solution passes, and the method further comprises:
 adjusting the flow rates of the first and second openings by adjusting the adjustable slit of the flow regulator of each one the first and second openings.   
     
     
         12 . The method of  claim 11 , wherein the flow rates of the first and second openings are adjusted by controlling the flow regulator to adjust either a slit width of the adjustable slit or an iris diaphragm of the adjustable slit. 
     
     
         13 . The method of  claim 8 , wherein, in response to a determination that the differential flow rate is within the acceptable range, continuing the determining whether the differential flow rate is within the acceptable range. 
     
     
         14 . The method of  claim 8 , further comprising recirculating the plating solution that has flowed through the first and second openings to the entry port. 
     
     
         15 . An electrochemical plating method, the method comprising:
 feeding a plating solution into a cell chamber, the cell chamber comprising a sidewall, a plurality of openings passing through the sidewall, and flow regulators connected to the openings and configured to adjust a flow of the plating solution through the openings;   measuring flow rates of the plating solution through the openings;   determining whether a differential flow rate of the flow rates of the plating solution through the openings is within an acceptable range; and   in response to a determination that the differential flow rate is not within the acceptable range, actuating one or more of the flow regulators to adjust the differential flow rate to within the acceptable range.   
     
     
         16 . The method of  claim 15 , wherein the actuating the one or more flow regulators to adjust the differential flow rate to within the acceptable range comprises adjusting a slit mechanism in the one or more flow regulators to adjust the flow of the plating solution. 
     
     
         17 . The method of  claim 15 , wherein, in response to a determination that the differential flow rate is within the acceptable range, continuing the determining whether the differential flow rate is within the acceptable range. 
     
     
         18 . The method of  claim 15 , further comprising recirculating the plating solution that has flowed through the openings to the cell chamber. 
     
     
         19 . The method of  claim 15 , wherein, when the differential flow rate is higher than the acceptable range, the actuating the one or more flow regulators decreases the flow of the plating solution therethrough. 
     
     
         20 . The method of  claim 15 , wherein, when the differential flow rate is lower than the acceptable range, the actuating the one or more flow regulators increases the flow of the plating solution therethrough.