Surface pre-treatment for enhancement of nucleation of high dielectric constant materials

Abstract

Embodiments of the present invention relate to a surface preparation treatment for the formation of thin films of high k dielectric materials over substrates. One embodiment of a method of forming a high k dielectric layer over a substrate includes pre-cleaning a surface of a substrate to remove native oxides, pre-treating the surface of the substrate with a hydroxylating agent, and forming a high k dielectric layer over the surface of the substrate. One embodiment of a method of forming a hafnium containing layer over a substrate includes introducing an acid solution to a surface of a substrate, introducing a hydrogen containing gas and an oxygen containing gas to the surface of the substrate, and forming a hafnium containing layer over the substrate.

1 . A method for forming a high dielectric constant layer on a substrate, comprising: 
 pre-cleaning a surface of the substrate to remove native oxides;    forming a hydroxylating gas by combining a gas containing molecular hydrogen and another gas containing molecular oxygen;    exposing the substrate to the hydroxylating gas to form a hydroxylated surface thereon; and    forming a dielectric material on the substrate, comprising: 
 forming a hafnium oxide layer during an atomic layer deposition process; and  
 forming a hafnium silicate layer on the hafnium oxide layer during another atomic layer deposition process.  
   
   
   
       2 . The method of  claim 1 , wherein the native oxides are removed by exposing the surface of the substrate to hydrofluoric acid solution during the pre-cleaning.  
   
   
       3 . The method of  claim 1 , further comprising: 
 exposing the substrate to a non-reactive gas while forming the hydroxylating surface thereon.    
   
   
       4 . The method of  claim 1 , wherein a ratio of the gas containing molecular oxygen to the gas containing molecular hydrogen is between about 65:35 to about 99.9:0.1.  
   
   
       5 . (canceled)  
   
   
       6 . The method of  claim 1 , wherein the hafnium oxide layer and the hafnium silicate layer comprise a different concentration of hafnium.  
   
   
       7 . (canceled)  
   
   
       8 . A method of forming a high dielectric constant layer over a substrate, comprising: 
 pre-cleaning a surface of the substrate to remove native oxides;    forming a hydroxylating gas by combining a gas containing molecular hydrogen and another gas containing molecular oxygen or nitrous oxide;    exposing the substrate to the hydroxylating gas to form a hydroxylated surface thereon; and    forming a dielectric material on the substrate, comprising: 
 forming a plurality of hafnium silicate layers by atomic layer deposition, where each hafnium silicate layer comprises different proportions of hafnium, silicon, and oxygen atoms.  
   
   
   
       9 . The method of  claim 8 , wherein the native oxides are removed by exposing the surface of the substrate to a hydrofluoric acid solution during the pre-cleaning.  
   
   
       10 . The method of  claim 8 , further comprising: 
 exposing the substrate to a non-reactive gas while forming the hydroxylating surface thereon.    
   
   
       11 . The method of  claim 8 , wherein an upper hafnium silicate layer comprises more silicon than a lower layer.  
   
   
       12 . The method of  claim 8 , wherein each hafnium silicate layer comprises a different concentration of hafnium.  
   
   
       13 . A method of forming a high dielectric constant layer over a substrate, comprising: 
 pre-cleaning a surface of the substrate to remove native oxides;    forming a hydroxylating gas by combining a gas containing molecular hydrogen and another gas containing molecular oxygen or nitrous oxide;    exposing the substrate to the hydroxylating gas to form a hydroxylated surface thereon; and    forming a dielectric material on the substrate, comprising: 
 forming a plurality of hafnium silicate layers by atomic layer deposition, wherein the plurality of hafnium silicate layers comprises a combination of the same hafnium silicate layers and different hafnium silicate layers.  
   
   
   
       14 .- 15 . (canceled)  
   
   
       16 . The method of  claim 8 , wherein each hafnium silicate layer comprises a different concentration of silicon.  
   
   
       17 . A method for forming a high dielectric constant layer on a substrate, comprising: 
 pre-cleaning a surface of the substrate to remove native oxides;    forming a hydroxylating gas by combining a gas containing molecular hydrogen and another gas containing oxygen;    exposing the substrate to the hydroxylating gas to form a hydroxylated surface thereon; and    forming the high dielectric constant material on the substrate, further comprising: 
 forming a plurality of hafnium containing layers by atomic layer deposition.  
   
   
   
       18 . The method of  claim 17 , wherein an upper hafnium containing layer comprises more silicon than a lower layer.  
   
   
       19 . The method of  claim 17 , wherein each hafnium containing layer comprises a different concentration of hafnium.  
   
   
       20 . The method of  claim 17 , wherein each hafnium containing layer comprises a different composition.  
   
   
       21 . The method of  claim 17 , wherein the plurality of hafnium containing layers comprises a combination of the same hafnium containing layers and different hafnium containing layers.  
   
   
       22 . The method of  claim 17 , wherein the plurality of hafnium containing layers comprise hafnium silicate layers.  
   
   
       23 . The method of  claim 22 , wherein each hafnium silicate layer comprises a different concentration of hafnium.  
   
   
       24 . The method of  claim 22 , wherein each hafnium silicate layer comprises a different concentration of silicon.  
   
   
       25 . The method of  claim 17 , wherein the oxygen containing gas comprises molecular oxygen or nitrous oxide.  
   
   
       26 . A method for forming a high dielectric constant layer on a substrate, comprising: 
 pre-cleaning a surface of the substrate to remove native oxides;    forming a hydroxylating gas by combining a gas containing molecular hydrogen and another gas containing molecular oxygen;    exposing the substrate to the hydroxylating gas to form a hydroxylated surface thereon; and    forming a dielectric material on the substrate, comprising: 
 forming a plurality of hafnium containing layers by plasma enhanced vapor deposition.  
   
   
   
       27 . The method of  claim 26 , wherein an upper hafnium containing layer comprises more silicon than a lower layer.  
   
   
       28 . The method of  claim 26 , wherein each hafnium containing layer comprises a different concentration of hafnium.  
   
   
       29 . The method of  claim 26 , wherein each hafnium containing layer comprises a different concentration.  
   
   
       30 . The method of  claim 26 , wherein the plurality of hafnium containing layers comprises a combination of the same hafnium containing layers and different hafnium containing layers.  
   
   
       31 . The method of  claim 26 , wherein the plurality of hafnium containing layers comprise hafnium silicate layers.  
   
   
       32 . The method of  claim 31 , wherein each hafnium silicate layer comprises a different concentration of hafnium.  
   
   
       33 . The method of  claim 31 , wherein each hafnium silicate layer comprises a different concentration of silicon.  
   
   
       34 . The method of  claim 26 , wherein the plasma enhanced vapor deposition is an atomic layer deposition process.  
   
   
       35 . The method of  claim 26 , wherein the plasma enhanced vapor deposition is a chemical vapor deposition process.