Method for removing oxides

Abstract

A method for removing native oxides from a substrate surface is provided. In one embodiment, the method comprises positioning a substrate having an oxide layer into a processing chamber, generating a plasma of a reactive species from a gas mixture within the processing chamber, exposing the substrate to the reactive species while forming a volatile film on the substrate and maintaining the substrate at a temperature below 65° C., heating the substrate to a temperature of at least about 75° C. to vaporize the volatile film and remove the oxide layer, and depositing a first layer on the substrate after heating the substrate.

1 . A deposition method comprising:
 positioning a substrate having an oxide layer into a processing chamber;   generating a plasma of a reactive species from a gas mixture within the processing chamber;   exposing the substrate to the reactive species while forming a volatile film on the substrate and maintaining the substrate at a temperature below 65° C.;   positioning the substrate between about 10 mils and about 200 mils from a heated showerhead within the processing chamber;   heating the substrate to a temperature of at least about 75° C. to vaporize the volatile film via heat radiated from the showerhead; and   depositing a first layer on the substrate after heating the substrate.   
     
     
         2 . The method of  claim 1 , wherein the first layer is deposited by a process selected from cyclical layer deposition, atomic layer deposition, chemical vapor deposition and physical vapor deposition. 
     
     
         3 . The method of  claim 1 , wherein the substrate comprises one or more of monocrystalline silicon and polycrystalline silicon. 
     
     
         4 . The method of  claim 1 , wherein the substrate comprises one or more of silicon oxide, germanium, carbon, gallium arsenide, glass, sapphire, conductive material and dielectric material. 
     
     
         5 . The method of  claim 4 , wherein the conductive material is selected from metal, metal nitride, metal alloy, and combinations thereof. 
     
     
         6 . The method of  claim 4 , wherein the dielectric material is selected from silicon dioxide, organosilicates, carbon doped silicon oxides and combinations thereof. 
     
     
         7 . The method of  claim 4 , wherein the substrate comprises silicon doped with a dopant selected from boron, arsenic, phosphorus, aluminum, gallium, germanium and carbon. 
     
     
         8 . The method of  claim 2 , wherein the exposing, the positioning, and the heating are performed under vacuum in a processing system without breaking vacuum prior to the depositing. 
     
     
         9 . The method of  claim 8 , wherein the exposing, the positioning, the heating, and the depositing occur in a multi-chambered processing system. 
     
     
         10 . The method of  claim 1 , wherein the substrate is heated to a temperature of at least 100° C. 
     
     
         11 . The method of  claim 10 , wherein the substrate is heated to a temperature in the range from at least 100° C. to about 200° C. 
     
     
         12 . The method of  claim 1 , wherein the reactive species is selected from ammonia fluoride, ammonium hydrogen fluoride and combinations thereof. 
     
     
         13 . The method of  claim 12 , wherein the volatile film comprises ammonium hexafluorosilicate ((NH 4 ) 2 SiF 6 ). 
     
     
         14 . The method of  claim 1 , wherein the first layer comprises a metal layer. 
     
     
         15 . The method of  claim 14 , further comprising forming an insulating layer on the metal layer. 
     
     
         16 . The method of  claim 15 , wherein the insulating layer comprises one of silicon oxide, borophosphosilicate glass and phosphosilicate glass. 
     
     
         17 . The method of  claim 14 , wherein the metal layer comprises a metal silicide layer selected from silicides of tungsten, tantalum, molybdenum and combinations thereof. 
     
     
         18 . The method of  claim 14 , wherein the metal layer comprises one of aluminum, copper, cobalt, nickel, silicon, titanium, palladium, hafnium, boron, tungsten, tantalum and combinations thereof. 
     
     
         19 . The method of  claim 1 , wherein the gas mixture comprises a molar ratio of ammonia to nitrogen trifluoride of at least 3:1. 
     
     
         20 . The method of  claim 1 , wherein the gas mixture comprises ammonia, nitrogen trifluoride and a carrier gas, and wherein the gas mixture comprises a total volume of the ammonia and the nitrogen trifluoride within a range from about 0.05% to about 20%.