Silver selenide film stoichiometry and morphology control in sputter deposition

Abstract

A method of sputter depositing silver selenide and controlling the stoichiometry and nodular defect formations of a sputter deposited silver-selenide film. The method includes depositing silver-selenide using a sputter deposition process at a pressure of about 0.3 mTorr to about 10 mTorr. In accordance with one aspect of the invention, an RF sputter deposition process may be used preferably at pressures of about 2 mTorr to about 3 mTorr. In accordance with another aspect of the invention, a pulse DC sputter deposition process may be used preferably at pressures of about 4 mTorr to about 5 mTorr.

1 - 75 . (canceled) 
   
   
       76 . A resistance variable memory device comprising:
 a silver-selenide film deposited onto a chalcogenide glass layer, the silver-selenide film deposited using a sputter deposition pressure varying in a range from about 0.3 mTorr to about 10 mTorr, having a formula of Ag x Se, where x is about 2, and having substantially no nodular defects.   
   
   
       77 . The device of  claim 76  wherein said silver-selenide film has a silver concentration of less than about 67.5 atomic weight percent. 
   
   
       78 . The device of  claim 77  wherein said silver-selenide film has a silver concentration of about 67 atomic weight percent. 
   
   
       79 . The device of  claim 77  wherein said silver-selenide film has a silver concentration of about 66.7 atomic weight percent. 
   
   
       80 . A resistance variable memory device comprising:
 a silver-selenide film comprising:
 a silver-selenide target formed onto a chalcogenide glass layer, wherein the silver-selenide target has a silver concentration of less than about 67.5 atomic weight percent, has the formula of Ag x Se, where x is about 2, and has substantially no nodular defects. 
   
   
   
       81 . The device of  claim 80  wherein said silver-selenide film has a silver concentration of about 67 atomic weight percent. 
   
   
       82 . The device of  claim 81  wherein said silver-selenide film has a silver concentration of about 66.7 atomic weight percent. 
   
   
       83 . A resistance variable memory device comprising:
 a silver-selenide target pulse DC sputter deposited onto a chalcogenide glass layer deposited at a pressure range between about 0.3 mTorr and about 10 mTorr, said silver-selenide target having a silver concentration of about 66.7 atomic weight percent, and   a silver-selenide film having substantially no nodular defects from said sputtered target, the silver-selenide film having the formula of Ag x Se, where x is about 2.   
   
   
       84 . The device of  claim 83  wherein said silver-selenide film has a silver concentration of less than about 67.5 atomic weight percent. 
   
   
       85 . The device of  claim 84  wherein said silver-selenide film has a silver concentration of about 67 atomic weight percent. 
   
   
       86 . The device of  claim 84  wherein said silver-selenide film has a silver concentration of about 66.7 atomic weight percent. 
   
   
       87 . The device of  claim 83  wherein said pressure range is between about 4 mTorr and about 5 mTorr. 
   
   
       88 . A resistance variable memory device comprising:
 a silver-selenide target having a silver concentration of about 66.7 atomic weight percent; and   a silver-selenide film formed from said sputtered target, said silver-selenide film having the formula of Ag x Se, where x is about 2 and having substantially no nodular defects.   
   
   
       89 . A resistance variable memory device comprising:
 a silver-selenide film deposited onto a chalcogenide glass layer, the silver-selenide film having a formula of Ag x Se, where x is about 2, and having substantially no nodular defects.   
   
   
       90 . The device of  claim 89  wherein said silver-selenide film has a silver concentration of less than about 67.5 atomic weight percent. 
   
   
       91 . The device of  claim 90  wherein said silver-selenide film has a silver concentration of about 67 atomic weight percent. 
   
   
       92 . The device of  claim 90  wherein said silver-selenide film has a silver concentration of about 66.7 atomic weight percent.