Low resistivity films containing molybdenum

Abstract

Provided herein are low resistance metallization stack structures for logic and memory applications and related methods of fabrication. In some implementations, the methods involve providing a tungsten (W)-containing layer on a substrate; and depositing a molybdenum (Mo)-containing layer on the W-containing layer. In some implementations, the methods involve depositing a Mo-containing layer directly on a dielectric or titanium nitride (TiN) substrate without an intervening W-containing layer.

1 .- 17 . (canceled) 
     
     
         18 . A method comprising:
 providing a substrate comprising a feature having a dielectric surface;   forming a molybdenum layer directly on the dielectric surface without an intervening diffusion barrier layer.   
     
     
         19 . The method of  claim 18 , wherein forming the molybdenum layer comprises forming a reducing agent layer on the dielectric surface. 
     
     
         20 . The method of  claim 19 , wherein forming the molybdenum layer further comprises exposing the reducing agent layer to a molybdenum-containing precursor. 
     
     
         21 . The method of  claim 20 , wherein the reducing agent layer is converted to molybdenum by the exposure. 
     
     
         22 . The method of  claim 19 , wherein the reducing agent layer is conformal to the feature. 
     
     
         23 . The method of claim  2 , wherein the reducing agent layer is between 10 Angstroms and 50 Angstroms thick. 
     
     
         24 . The method of  claim 18 , wherein the dielectric surface is a silicon oxide surface. 
     
     
         25 . The method of  claim 18 , wherein the dielectric surface is a silicon nitride surface 
     
     
         26 . The method of  claim 18 , wherein the dielectric surface is an aluminum oxide surface. 
     
     
         27 . The method of  claim 18 , wherein the feature further comprises a conductive surface. 
     
     
         28 . The method of  claim 18 , wherein molybdenum layer has less than 1 (atomic) % impurities. 
     
     
         29 . The method of  claim 18 , wherein molybdenum layer is formed from one of: molybdenum hexafluoride (MoF 6 ), molybdenum pentachloride (MoCl 5 ), molybdenum dichloride dioxide (MoO 2 Cl 2 ), molybdenum tetrachloride oxide (MoOCl 4 ), and molybdenum hexacarbonyl (Mo(CO) 6 ). 
     
     
         30 . The method of  claim 18 , wherein molybdenum layer is formed from an organometallic precursor. 
     
     
         31 . A method comprising:
 providing a substrate comprising a feature having a dielectric surface;   forming a conformal reducing agent layer in the feature including directly on the dielectric surface; and   exposing the reducing agent layer to a molybdenum-containing precursor to form a conformal molybdenum layer including directly on the dielectric surface.   
     
     
         32 . The method of  claim 31 , wherein the reducing agent layer is between 10 Angstroms and 50 Angstroms thick. 
     
     
         33 . The method of  claim 31 , wherein the dielectric surface is a silicon oxide surface, a silicon nitride surface, or an aluminum oxide surface. 
     
     
         34 . The method of  claim 31 , wherein the molybdenum precursor is one of molybdenum hexafluoride (MoF 6 ), molybdenum pentachloride (MoCl 5 ), molybdenum dichloride dioxide (MoO 2 Cl 2 ), molybdenum tetrachloride oxide (MoOCl 4 ), and molybdenum hexacarbonyl (Mo(CO) 6 ). 
     
     
         35 . The method of  claim 31 , wherein molybdenum precursor is an organometallic precursor. 
     
     
         36 . A method comprising:
 depositing a molybdenum-containing nucleation layer on a substrate using a first reducing agent; and   depositing by chemical vapor deposition (CVD) a molybdenum bulk layer on the molybdenum nucleation layer using a second reducing agent, wherein the second reducing agent is different from the first reducing agent.   
     
     
         37 . The method of  claim 36 , wherein the molybdenum bulk layer is deposited by a reducing a molybdenum compound selected from: molybdenum hexafluoride (MoF 6 ), molybdenum pentachloride (MoCl 5 ), molybdenum dichloride dioxide (MoO 2 Cl 2 ), molybdenum tetrachloride oxide (MoOCl 4 ), and molybdenum hexacarbonyl (Mo(CO) 6 ).