Capacitor fabrication methods and capacitor constructions

Abstract

A capacitor fabrication method may include atomic layer depositing a conductive barrier layer to oxygen diffusion over the first electrode. A method may instead include chemisorbing a layer of a first precursor at least one monolayer thick over the first electrode and chemisorbing a layer of a second precursor at least one monolayer thick on the first precursor layer, a chemisorption product of the first and second precursor layers being comprised by a layer of a conductive barrier material. The barrier layer may be sufficiently thick and dense to reduce oxidation of the first electrode by oxygen diffusion from over the barrier layer. An alternative method may include forming a first capacitor electrode over a substrate, the first electrode having an inner surface area per unit area and an outer surface area per unit area that are both greater than an outer surface area per unit area of the substrate. A capacitor dielectric layer and a second capacitor electrode may be formed over the dielectric layer. The method may further include forming rugged polysilicon over the substrate, the first electrode being over the rugged polysilicon. Accordingly, the outer surface area of the first electrode can be at least 30% greater than the outer surface area of the substrate without the first electrode including polysilicon.

1 - 33 . (canceled)  
   
   
       34 . A capacitor fabrication method comprising: 
 forming a first capacitor electrode containing HSG polysilicon over a substrate;    atomic layer depositing a conductive layer on and in physical contact with the first electrode, the conductive layer having a thickness of from about 50 to about 500 Angstroms and containing WN, WSiN, TaN, TiN, TiSiN, Pt, Pt alloys, Ir, Ir alloys, Pd, Pd alloys, RuO x , or IrO x ;    forming an oxygen-containing capacitor dielectric layer on and in physical contact with the conductive layer, the dielectric layer including Ta 2 O 5 , ZrO 2 , WO 3 , Al 2 O 3 , HfO 2 , barium strontium titanate, or strontium titanate; and    forming a second capacitor electrode over the dielectric layer.    
   
   
       35 . The method of  claim 34  wherein the atomic layer deposited conductive layer has a thickness of from about 200 to about 500 Angstroms.  
   
   
       36 . The method of  claim 34  further comprising cleaning the first electrode prior to the atomic layer depositing by a method comprising HF dip, HF vapor clean, or NF 3  remote plasma.  
   
   
       37 . The method of  claim 34  wherein the atomic layer deposited conductive layer has a thickness and a density effective to reduce oxidation of the first electrode by oxygen from over the conductive layer, including from the dielectric layer.  
   
   
       38 . The method of  claim 34  wherein the substrate comprises a semiconductive wafer.  
   
   
       39 . The method of  claim 34  wherein the atomic layer deposited conductive layer comprises WN.  
   
   
       40 . The method of  claim 34  wherein the atomic layer deposited conductive layer comprises TiN.  
   
   
       41 . The method of  claim 34  wherein the capacitor dielectric layer comprises Al 2 O 3 .  
   
   
       42 . The method of  claim 34  wherein the second capacitor electrode comprises TiN.  
   
   
       43 . The method of  claim 34  wherein the atomic layer deposited conductive layer comprises TiN, the capacitor dielectric layer comprises Al 2 O 3 , and the second capacitor electrode comprises TiN.  
   
   
       44 . The method of  claim 34  wherein the atomic layer depositing occurs at a temperature of from about 100 to about 600° C. and at a pressure of from about 0.1 to about 10 Torr.  
   
   
       45 . A capacitor fabrication method comprising: 
 forming a first capacitor electrode containing polysilicon over a substrate;    atomic layer depositing a conductive layer on and in physical contact with the first electrode, the conductive layer having a thickness of from about 200 to about 500 Angstroms and containing TiN;    forming an oxygen-containing capacitor dielectric layer on and in physical contact with the conductive layer, the dielectric layer including Ta 2 O 5 , ZrO 2 , WO 3 , Al 2 O 3 , HfO 2 , barium strontium titanate, or strontium titanate; and    forming a second capacitor electrode on and in physical contact with the dielectric layer, the second capacitor electrode containing TiN.    
   
   
       46 . The method of  claim 45  wherein the capacitor dielectric layer comprises Al 2 O 3 .  
   
   
       47 . The method of  claim 45  wherein the substrate comprises a semiconductive wafer.  
   
   
       48 . The method of  claim 45  wherein the polysilicon comprises HSG polysilicon.  
   
   
       49 . A capacitor fabrication method comprising: 
 forming a first capacitor electrode containing polysilicon over a substrate;    atomic layer depositing a conductive layer on and in physical contact with the first electrode, the conductive layer containing WN;    forming an oxygen-containing capacitor dielectric layer on and in physical contact with the conductive layer, the dielectric layer including Ta 2 O 5 , ZrO 2 , WO 3 , Al 2 O 3 , HfO 2 , barium strontium titanate, or strontium titanate; and    forming a second capacitor electrode on and in physical contact with the dielectric layer, the second capacitor electrode containing TiN.    
   
   
       50 . The method of  claim 49  wherein the capacitor dielectric layer comprises Al 2 O 3 .  
   
   
       51 . The method of  claim 49  wherein the substrate comprises a semiconductive wafer.  
   
   
       52 . The method of  claim 49  wherein the polysilicon comprises HSG polysilicon.  
   
   
       53 . The method of  claim 49  wherein the atomic layer deposited conductive layer has a thickness of from about 200 to about 500 Angstroms.