Forming sublithographic heaters for phase change memories

Abstract

A phase change memory with a heater with sublithographic dimensions may be achieved, in some embodiments, with lower thermal budget. The phase change memory may use a controlled etching process to reduce the lateral dimension of the heater.

1 . A method comprising:
 exposing a side of a phase change memory heater material to an etchant to reduce a lateral dimension of said heater.   
   
   
       2 . The method of  claim 1  including forming an upstanding heater and exposing a portion of its vertical extent. 
   
   
       3 . The method of  claim 1  including etching said heater including said exposed vertical extent. 
   
   
       4 . The method of  claim 1  including using a damascene process to form said heater. 
   
   
       5 . The method of  claim 4  including removing a portion of a dielectric surrounding said heater. 
   
   
       6 . The method of  claim 3  including covering said etched heater with an insulator. 
   
   
       7 . The method of  claim 3  including planarizing said etched heater. 
   
   
       8 . The method of  claim 7  including covering said etched heater with an insulator and then planarizing said etched heater. 
   
   
       9 . The method of  claim 7  including covering said etched heater with a sacrificial material to improve planarization controllability. 
   
   
       10 . The method of  claim 1  including forming said heater in an inverted T-shape. 
   
   
       11 . A phase change memory comprising:
 a chalcogenide material; and   a heater for said chalcogenide material, said heater having an inverted T-shape with a horizontally extending portion and a vertically extending portion, said vertically extending portion adjacent said material.   
   
   
       12 . The memory of  claim 11  wherein said vertically extending portion has a sublithographic lateral extent. 
   
   
       13 . The memory of  claim 12  wherein said vertically extending portion tapers inwardly as it extends towards said horizontally extending portion. 
   
   
       14 . The memory of  claim 13  wherein said horizontally extending portion includes a curved surface that extends into said vertically extending portion. 
   
   
       15 . The memory of  claim 11  wherein said heater horizontally extending portion is wider in a lateral direction than said vertically extending portion. 
   
   
       16 . The memory of  claim 11  wherein said heater vertically extending portion is in contact with said chalcogenide material. 
   
   
       17 . The memory of  claim 11  without side wall spacers. 
   
   
       18 . A system comprising:
 a processor;   a battery to supply power to said processor; and   a phase change memory coupled to said processor, said phase change memory including a chalcogenide material and a heater having an inverted T-shape, having a wider and narrower portion, said narrower portion of the heater being closer to said chalcogenide material.   
   
   
       19 . The system of  claim 18  wherein said narrower portion has a sublithographic lateral extent. 
   
   
       20 . The system of  claim 19  wherein said wider portion tapers inwardly as it extends towards said narrower portion. 
   
   
       21 . The system of  claim 20  wherein said wider portion includes a curved surface that extends into said narrower portion. 
   
   
       22 . The system of  claim 18  wherein said wider portion is wider in a lateral direction than said narrower portion. 
   
   
       23 . The system of  claim 18  wherein said narrower portion is in contact with said chalcogenide material.