In-Situ Formation of Metal Insulator Metal Capacitors

Abstract

The invention describes an in-situ method of fabricating a metal insulator metal (MIM) capacitor and products formed by the same. The method utilizes atomic layer deposition (ALD) or metal-organic chemical vapor deposition (MOCVD). In the method, a metal precursor is sequentially reacted with a nitrogen source, oxidant, and then a nitrogen source again. Reaction with the nitrogen source generates the outermost conductive metal nitride (MN) layers ( 121 ). Reaction with the oxidant generates an inner dielectric metal oxide (MO x ) layer ( 110 ). Alternatively, or in addition, the metal precursor can be reacted with a mixture of oxidant and nitrogen source to generate inner dielectric layer(s) ( 231, 232, 310 ) of metal oxynitride (MO x N y ). Because the same metal is used throughout the capacitor, the layers in the MIM capacitor exhibits excellent compatibility and stability.

1 . A process for forming a metal-insulator-metal (MIM) capacitor on a substrate, characterized in that: a single metal precursor is reacted sequentially to form each of the metal, insulator and metal layers of said MIM capacitor. 
   
   
       2 . The process according to  claim 1 , wherein the single metal precursor is a metal amide or metal imide selected from the group consisting of: Zr, Ti, Hf, Ta, V, and Nb. 
   
   
       3 . The process according to  claim 1 , wherein the metal precursor is a metal amide or metal imide selected from the group consisting of W and Mo. 
   
   
       4 . The process according to  claim 1 , further comprising: reacting said single metal precursor with a nitrogen source in one sequential step and wherein the nitrogen source is selected from the group consisting of ammonia, atomic nitrogen, hydrazine, or primary, secondary, and tertiary alkyl amines. 
   
   
       5 . The process according to  claim 1 , further comprising: reacting said single metal precursor with an oxidant in one sequential step and wherein the oxidant is selected from the group consisting of oxygen, ozone, atomic oxygen, nitrous oxide, or hydrogen peroxide. 
   
   
       6 . The process according to  claim 1 , wherein the metal precursor is a metal amide of the form:
   M(NR 1 R 2 ),   where M is the metal element, N is nitrogen, and R 1  and R 2  are, independently, selected from the following groups: hydrogen, substituted or un-substituted linear, branched, cyclic, and aromatic alkyls and n is 4 or 5.   
   
   
       7 . The process according to  claim 6 , wherein the metal element M is selected from the group consisting of Zr, Ti, Hf, Ta, V, Nb, W and Mo. 
   
   
       8 . The process according to  claim 1 , wherein the metal precursor is a metal amide of the form:
   (R 3 —N═) m M′(NR 4 R 5 ) p      where M is the metal element, and R 3 , R 4 , and R 5  are, independently, selected from the following groups: hydrogen, substituted or un-substituted linear, branched, cyclic and aromatic alkyls.   
   
   
       9 . The process according to  claim 8 , wherein the metal element M is selected from the group consisting of Zr, Ti, Hf, Ta, V, Nb, W and Mo. 
   
   
       10 . The process according to  claim 8 , wherein m is 1 and p is 3 when M is either Ta or Nb. 
   
   
       11 . The process according to  claim 8 , wherein m is 2 and p is 2 when M is either W or Mo. 
   
   
       12 . A metal-insulator-metal (MIM) capacitor, comprising: layers of metal oxide, sandwiched between layers of metal nitride; and
 wherein the metal in each of said metal oxide and metal nitride layers is the same.   
   
   
       13 . The MIM capacitor according to  claim 12  further comprising:
 an intermediate metal oxynitride layer sandwiched between the metal oxide and metal nitride layers.   
   
   
       14 . The MIM capacitor according to  claim 13  wherein the intermediate metal oxynitride layer is formed of the same metal as the metal in the metal oxide and metal nitride layers. 
   
   
       15 . The MIM capacitor according to  claim 12  wherein the layers of metal oxide comprise: metal oxynitride materials, or combinations of metal oxides and metal oxynitride materials.