Carbon nanotubes bonding on metallic electrodes

Abstract

A method for large scale bonding carbon nanotubes on metallic electrodes is disclosed. The method includes that the wafer with a number of patterned electrodes deposited by CNTs via dielectrophoresis method is put onto the pedestal of our designed RF induction heating system. Then, the winding with alternating current induces scroll current on the surface of metallic electrodes due to skin effect. In this case, the current will generate Joule heat which could melt the surface metal of the electrodes. Finally, the CNTs will sink into the surface of the electrodes after short time heating. By varying the parameters of the RF source we can control the bonding process.

1 . A method for large scale bonding carbon nanotubes on metallic electrodes, comprising: providing a wafer with number of patterned electrodes that is deposited by CNTs via dielectrophoresis method; putting the wafer onto the pedestal of the designed RF induction heating system; turning on the power and heating the wafer for a short time; cooling the wafer in vacuum or protection gas filled environment. 
   
   
       2 . The method according to  claim 1 , wherein said a RF induction heating system including RF power, water cooling system, winding and glass pedestal. 
   
   
       3 . The method according to  claim 2 , wherein said the structure of winding can be varied according to electrodes patterns. 
   
   
       4 . The method according to  claim 2 , wherein said the water cooling system comprises a spiral pipe that coated outsaid of the winding, and the cooling is realized by flowing water through the pipe. 
   
   
       5 . The method according to  claim 1 , wherein said RF induction heating process comprises tuning the parameters of frequency, power and heating time. 
   
   
       6 . The method according to  claim 5 , wherein said the frequency of the RF source is ranged from 200 KHz to 15 MHz. 
   
   
       7 . The method according to  claim 5 , wherein said the power of the RF source is ranged from 100 W to 500 W. 
   
   
       8 . The method according to  claim 5 , wherein said the time of heating is not longer than 1 minute. 
   
   
       9 . The method according to  claim 1 , wherein said the CNTs include individual carbon nanotubes, multi-wall carbon nanotubes and bundles of carbon nanotubes. 
   
   
       10 . The method according to  claim 1 , wherein said the material of electrodes includes metals or alloy. 
   
   
       11 . The method according to  claim 10 , wherein said the electrodes are fabricated by optical lithography and lift-off process. 
   
   
       12 . The method according to  claim 1 , wherein said the CNTs are dispersed in aqueous solution. 
   
   
       13 . The method according to  claim 1 , wherein said the CNTs are bridged between the pairs of electrodes by dielectrophoresis method. 
   
   
       14 . The method according to  claim 13 , wherein said the frequency of alternating current in dielectrophoresis is 100 KHz-10 MHz. 
   
   
       15 . The method according to  claim 13 , wherein said the voltage of dielectrophoresis is 1-5V. 
   
   
       16 . The method according to  claim 13 , wherein said the time of the dielectrophoresis is ranged from 10 second to 30 second.