Magnet-driven chemical-mechanical polishing

Abstract

This disclosure describes systems, methods, and devices related to enhanced plate polishing. A device may place a liquid between a plate and a wafer. The device may utilize a controller to vary a current flowing through an array of coils. The device may apply pressure on the plate to press against the liquid and the wafer.

What is claimed is: 
     
         1 . A system, comprising:
 a panel;   a holder device that holds the panel in place;   a liquid disposed on top of the panel;   a plate disposed on top of the liquid, wherein the plate is configured to apply pressure to the liquid;   an array of coils positioned underneath the holder; and   a controller configured to vary a current in the array of coils.   
     
     
         2 . The system of  claim 1 , wherein the panel is a wafer. 
     
     
         3 . The system of  claim 1 , wherein the liquid comprises at least one of a ferrofluid and a mixture of the ferrofluid with a chemical fluid. 
     
     
         4 . The system of  claim 3 , wherein varying the current with the controller causes a magnetic field within the ferrofluid or the mixture of the ferrofluid with the chemical. 
     
     
         5 . The system of  claim 4 , wherein magnetic field causes the ferrofluid to polish a first surface of the panel. 
     
     
         6 . The system of  claim 1 , wherein the array of coils or the panel sits above a springloaded frame, wherein the springloaded frame is configured to move laterally to vary a location of the magnetic field. 
     
     
         7 . The system of  claim 1 , wherein the panel and the plate are immobile. 
     
     
         8 . The system of  claim 1 , wherein the plate includes holes to allow a slurry used to polish the panel to flow. 
     
     
         9 . The system of  claim 1 , wherein the controller turns each coil of the array of coils to be on or off based on a pattern. 
     
     
         10 . The system of  claim 1 , wherein the liquid is a magnetic slurry is either coated with a magnetic material or has a magnetic core. 
     
     
         11 . The system of  claim 1 , further comprising a magnetic separation system to separate and reuse magnetic material in the liquid. 
     
     
         12 . A non-transitory computer-readable medium storing computer-executable instructions which when executed by one or more processors result in performing operations comprising:
 placing a liquid between a plate and a wafer;   utilizing a controller to vary a current flowing through an array of coils; and   applying pressure on the plate to press against the liquid and the wafer.   
     
     
         13 . The non-transitory computer-readable medium of  claim 12 , wherein the liquid comprises at least one of a ferrofluid and a mixture of the ferrofluid with a chemical fluid. 
     
     
         14 . The non-transitory computer-readable medium of  claim 13 , wherein varying the current causes a magnetic field within the ferrofluid or the mixture of the ferrofluid with the chemical. 
     
     
         15 . The non-transitory computer-readable medium of  claim 12 , wherein the array of coils or the panel sits above a springloaded frame. 
     
     
         16 . The non-transitory computer-readable medium of  claim 15 , wherein the springloaded frame is configured to move laterally to vary a location of the magnetic field. 
     
     
         17 . The non-transitory computer-readable medium of  claim 12 , wherein the plate includes holes to allow a slurry used to polish the panel to flow. 
     
     
         18 . The non-transitory computer-readable medium of  claim 12 , wherein the controller turns each coil of the array of coils to be on or off based on a pattern. 
     
     
         19 . A method, comprising:
 placing a liquid between a plate and a wafer;   utilizing a controller to vary a current flowing through an array of coils; and   applying pressure on the plate to press against the liquid and the wafer.   
     
     
         20 . The method of  claim 19 , wherein the controller turns each coil of the array of coils to be on or off based on a pattern