Safe handling of low energy, high dose arsenic, phosphorus, and boron implanted wafers

Abstract

A method of preventing toxic gas formation after an implantation process is disclosed. Certain dopants, when implanted into films disposed on a substrate, may react when exposed to moisture to form a toxic gas and/or a flammable gas. By in-situ exposing the doped film to an oxygen containing compound, dopant that is shallowly implanted into the layer stack reacts to form a dopant oxide, thereby reducing potential toxic gas and/or flammable gas formation. Alternatively, a capping layer may be formed in-situ over the implanted film to reduce the potential generation of toxic gas and/or flammable gas.

1 . A substrate processing method, comprising:
 forming an implanted film by implanting a dopant into a film on a substrate disposed in a processing chamber; and   exposing the implanted film to an oxygen containing plasma to form an oxide layer on the implanted film and trap the dopant within the implanted film prior to exposure of the implanted film to atmospheric oxygen.   
   
   
       2 . The method of  claim 1 , wherein the dopant is selected from the group consisting of arsenic, phosphorus, boron, and combinations thereof. 
   
   
       3 . The method of  claim 2 , wherein the oxygen containing plasma is produced from oxygen gas. 
   
   
       4 . The method of  claim 3 , wherein the implanting and the exposing occurs within the same processing chamber. 
   
   
       5 . The method of  claim 4 , wherein the plasma is generated by a capacitively coupled source. 
   
   
       6 . The method of  claim 5 , wherein the plasma is generated by an inductively coupled source in addition to the capacitively coupled source. 
   
   
       7 . The method of  claim 4 , wherein the plasma is generated by an inductively coupled source. 
   
   
       8 . The method of  claim 1 , further comprising exposing the implanted film to a hydrogen containing plasma separately from the oxygen containing plasma. 
   
   
       9 . The method of  claim 8 , wherein the exposing the implanted film to a hydrogen containing plasma occurs after the implanting and before exposing to an oxygen containing plasma. 
   
   
       10 . The method of  claim 9 , wherein the exposing to a hydrogen containing plasma and exposing to an oxygen containing plasma occurs a plurality of times. 
   
   
       11 . The method of  claim 8 , wherein the exposing the implanted film to a hydrogen containing plasma occurs after the implanting and after exposing to an oxygen containing plasma. 
   
   
       12 . The method of  claim 11 , wherein the exposing to a hydrogen containing plasma and exposing to an oxygen containing plasma occurs a plurality of times. 
   
   
       13 . The method of  claim 1 , further comprising depositing a capping layer over the oxide layer, wherein the capping layer is selected from the group consisting of a carbon layer, a silicon layer, a silicon oxide layer, a silicon nitride layer, a silicon carbide layer, an organic layer, and combinations thereof. 
   
   
       14 . The method of  claim 13 , further comprising etching the implanted film before the exposing, wherein the etching removes excess dopants and wherein the etching comprises exposing the implanted layer to a plasma formed from NF 3 . 
   
   
       15 . The method of  claim 13 , wherein the capping layer is removed without damaging the implanted film. 
   
   
       16 . The method of  claim 1 , wherein atmospheric oxygen includes moisture. 
   
   
       17 . The method of  claim 1 , wherein the plasma comprises a circulating plasma current. 
   
   
       18 . The method of  claim 1 , further comprising:
 annealing the oxide layer; and   depositing a capping layer on the oxide layer.   
   
   
       19 . A substrate processing method, comprising:
 forming an implanted film by implanting a dopant into a film on a substrate disposed in a processing chamber;   exposing the implanted film to a circulating plasma current containing oxygen to form an oxide layer on the implanted film and trap the dopant within the film prior to exposure of the implanted film to atmospheric oxygen; and   removing the oxide layer without damaging the implanted film.   
   
   
       20 . The method of  claim 19 , wherein the circulating plasma current is generated by an inductively coupled source.