Chemical vapor deposition methods of forming barium strontium titanate comprising dielectric layers, including such layers having a varied concentration of barium and strontium within the layer

Abstract

The invention a chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer having a varied concentration of barium and strontium, and/or titanium, within the layer. A substrate is positioned within a chemical vapor deposition reactor. Barium and strontium are provided within the reactor by flowing at least one metal organic precursor to the reactor. Titanium is provided within the reactor. One or more oxidizers are flowed to the reactor. In one aspect, conditions are provided within the reactor to be effective to deposit a barium strontium titanate comprising dielectric layer on the substrate from the reactants.

1 . A chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer having a varied concentration of barium and strontium within the layer, comprising: 
 positioning a substrate within a chemical vapor deposition reactor;    providing barium and strontium within the reactor by flowing at least one metal organic precursor to the reactor, and providing titanium within the reactor, and flowing at least one oxidizer to the reactor, under conditions effective to deposit a barium strontium titanate comprising dielectric layer on the substrate; the barium and strontium being provided within the reactor during all of the deposit of said layer at a substantially constant atomic ratio of barium to strontium; and    during said deposit, changing a rate of flow of the oxidizer to the reactor at least once to effect a change in relative atomic concentration of barium and strontium within the deposited barium strontium titanate comprising dielectric layer.    
     
     
         2 . The method of  claim 1  comprising changing the rate of flow at least twice.  
     
     
         3 . The method of  claim 1  comprising providing the barium and strontium within the reactor by flowing at least two metal organic precursors to the reactor, one of the precursors comprising barium, another of the precursors comprising strontium.  
     
     
         4 . The method of  claim 1  comprising providing the barium and strontium within the reactor by flowing at least two metal organic precursors to the reactor, one of the precursors comprising barium, another of the precursors comprising strontium, the one and the another precursors being fed to the reactor as a mixture in a single flow stream.  
     
     
         5 . The method of  claim 1  comprising providing the barium and strontium within the reactor during all of the deposit of said layer at substantially constant volumetric flow rates to the reactor.  
     
     
         6 . The method of  claim 1  wherein the oxidizer is inorganic.  
     
     
         7 . The method of  claim 1  wherein the oxidizer comprises NO x , where “x” is at least 1.  
     
     
         8 . The method of  claim 1  wherein the oxidizer comprises NO.  
     
     
         9 . The method of  claim 1  wherein the oxidizer comprises a single inorganic oxidizer consisting essentially of NO.  
     
     
         10 . The method of  claim 1  comprising flowing at least two oxidizers to the reactor.  
     
     
         11 . The method of  claim 1  comprising flowing at least two inorganic oxidizers to the reactor.  
     
     
         12 . The method of  claim 1  comprising flowing at least two inorganic oxidizers to the reactor, said oxidizers comprising at least O 3  and N 2 O.  
     
     
         13 . The method of  claim 1  comprising flowing at least two inorganic oxidizers to the reactor, said oxidizers comprising at least O 3  and NO x , where “x” is at least 1.  
     
     
         14 . The method of  claim 1  comprising flowing at least two inorganic oxidizers to the reactor, said oxidizers comprising at least O 2  and NO x .  
     
     
         15 . The method of  claim 1  comprising flowing at least two inorganic oxidizers to the reactor, said oxidizers comprising at least O 2  and N 2 O.  
     
     
         16 . The method of  claim 1  comprising flowing at least two inorganic oxidizers to the reactor, said oxidizers comprising at least N 2 O and NO x , where “x” is at least 1.  
     
     
         17 . A chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer having a varied concentration of titanium within the layer, comprising: 
 positioning a substrate within a chemical vapor deposition reactor;    providing barium and strontium within the reactor by flowing at least one metal organic precursor to the reactor, and providing titanium within the reactor, and flowing at least one oxidizer to the reactor, under conditions effective to deposit a barium strontium titanate comprising dielectric layer on the substrate; the barium and strontium being provided within the reactor during all of the deposit of said layer at a substantially constant atomic ratio of barium to strontium; and    during said deposit, changing a rate of flow of the oxidizer to the reactor at least once to effect a change in atomic concentration of titanium within the deposited barium strontium titanate comprising dielectric layer.    
     
     
         18 . The method of  claim 17  wherein the changing of a rate of flow of the oxidizer to the reactor at least once is also effective to effect a change in relative atomic concentration of barium and strontium within the deposited barium strontium titanate comprising dielectric layer.  
     
     
         19 . The method of  claim 17  comprising changing the rate of flow at least twice.  
     
     
         20 . The method of  claim 17  wherein the oxidizer is inorganic.  
     
     
         21 . The method of  claim 17  wherein the oxidizer comprises NO x , where “x” is at least 1.  
     
     
         22 . The method of  claim 17  wherein the oxidizer comprises NO.  
     
     
         23 . The method of  claim 17  wherein the oxidizer comprises a single inorganic oxidizer consisting essentially of NO.  
     
     
         24 . The method of  claim 17  comprising flowing at least two oxidizers to the reactor.  
     
     
         25 . The method of  claim 17  comprising flowing at least two inorganic oxidizers to the reactor.  
     
     
         26 . A chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer, comprising: 
 positioning a substrate within a chemical vapor deposition reactor; and    providing barium and strontium within the reactor by flowing at least one metal organic precursor to the reactor, and providing titanium within the reactor, and flowing oxidizers comprising at least O 3  and N 2 O to the reactor, under conditions effective to deposit a barium strontium titanate comprising dielectric layer on the substrate; the O 3  being present within the reactor during at least a portion of the deposit at greater than 10% by volume of the total volume of N 2 O and O 3  within the reactor.    
     
     
         27 . The method of  claim 26  wherein the portion comprises a majority portion.  
     
     
         28 . The method of  claim 26  wherein the portion comprises all of the deposit.  
     
     
         29 . The method of  claim 26  wherein the conditions are void of plasma and remote plasma.  
     
     
         30 . The method of  claim 26  wherein the conditions comprise at least one of plasma or remote plasma.  
     
     
         31 . The method of  claim 26  comprising flowing another inorganic oxidizer to the reactor during the deposit.  
     
     
         32 . A chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer, comprising: 
 positioning a substrate within a chemical vapor deposition reactor; and    providing barium and strontium within the reactor by flowing at least one metal organic precursor to the reactor, and providing titanium within the reactor, and flowing oxidizers comprising at least O 3  and NO x  to the reactor, where “x” is at least 1, under conditions effective to deposit a barium strontium titanate comprising dielectric layer on the substrate.    
     
     
         33 . The method of  claim 32  wherein “x” equals 1.  
     
     
         34 . The method of  claim 32  wherein “x” is more than 1.  
     
     
         35 . The method of  claim 32  comprising flowing another inorganic oxidizer to the reactor during the deposit.  
     
     
         36 . A chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer, comprising: 
 positioning a substrate within a chemical vapor deposition reactor; and    providing barium and strontium within the reactor by flowing at least one metal organic precursor to the reactor, and providing titanium within the reactor, and flowing oxidizers comprising at least O 2  and NO x  to the reactor, where “x” is at least 1, under conditions effective to deposit a barium strontium titanate comprising dielectric layer on the substrate.    
     
     
         37 . The method of  claim 36  wherein “x” equals 1.  
     
     
         38 . The method of  claim 36  wherein “x” is more than 1.  
     
     
         39 . The method of  claim 36  comprising flowing another inorganic oxidizer to the reactor during the deposit.  
     
     
         40 . A chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer, comprising: 
 positioning a substrate within a chemical vapor deposition reactor; and    providing barium and strontium within the reactor by flowing at least one metal organic precursor to the reactor, and providing titanium within the reactor, and flowing oxidizers comprising at least N 2 O and NO x  to the reactor, where “x” is at least 1, under conditions effective to deposit a barium strontium titanate comprising dielectric layer on the substrate, the NO x  being present within the reactor during at least a portion of the deposit at greater than 10% by volume of the total volume of N 2 O and NO x  within the reactor.    
     
     
         41 . The method of  claim 40  wherein “x” equals 1.  
     
     
         42 . The method of  claim 40  wherein “x” is more than 1.  
     
     
         43 . The method of  claim 40  comprising flowing another inorganic oxidizer to the reactor during the deposit.  
     
     
         44 . A chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer, comprising: 
 positioning a substrate within a chemical vapor deposition reactor; and    providing barium and strontium within the reactor by flowing at least one metal organic precursor to the reactor, and providing titanium within the reactor, and flowing oxidizers comprising at least O 2 , O 3  and NO x  to the reactor, where “x” is at least 1, under conditions effective to deposit a barium strontium titanate comprising dielectric layer on the substrate.    
     
     
         45 . The method of  claim 44  wherein “x” equals 1.  
     
     
         46 . The method of  claim 44  wherein “x” is more than 1.  
     
     
         47 . A chemical vapor deposition method of forming a barium strontium titanate comprising dielectric layer, comprising: 
 positioning a substrate within a chemical vapor deposition reactor; and    providing barium and strontium within the reactor by flowing at least one metal organic precursor to the reactor, and providing titanium within the reactor, and flowing oxidizers comprising at least O 2 , O 3  and N 2 O to the reactor, under conditions effective to deposit a barium strontium titanate comprising dielectric layer on the substrate.    
     
     
         48 . The method of  claim 47  wherein the conditions comprise receipt of the substrate by a susceptor, the susceptor having a temperature of less than or equal to 550° C.  
     
     
         49 . The method of  claim 47  wherein the deposited layer is substantially homogeneous.  
     
     
         50 . The method of  claim 47  wherein the deposited layer is not substantially homogeneous.  
     
     
         51 . The method of  claim 47  comprising flowing another inorganic oxidizer to the reactor during the deposit.