SEMICONDUCTOR STRUCTURES COMPRISING CRYSTALLINE PrCaMnO (PCMO) FORMED BY ATOMIC LAYER DEPOSITION

Abstract

Semiconductor structures include PrCaMnO (PCMO) material formed by atomic layer deposition. The PCMO material is formed by exposing a surface of a substrate to a manganese-containing precursor, an oxygen-containing precursor, a praseodymium-containing precursor and a calcium-containing precursor. The resulting PCMO material is crystalline.

What is claimed is: 
     
         1 . A semiconductor structure comprising:
 a crystalline PCMO material overlying a substrate, the crystalline PCMO material formed by a process comprising:
 exposing a surface of the substrate to each of a praseodymium-containing precursor comprising a cyclopentadienyl ligand (Cp), a calcium-containing precursor comprising a cyclopentadienyl ligand (Cp), a manganese-containing precursor, and an oxygen-containing precursor to deposit a PCMO material in a crystalline state over the substrate by an atomic layer deposition process conducted at a temperature of less than about 450° C. 
   
     
     
         2 . The semiconductor structure of  claim 1 , further comprising a plurality of metal components. 
     
     
         3 . The semiconductor structure of  claim 1 , wherein the crystalline PCMO material comprises Pr 0.7 Ca 0.3 MaO 3 , Pr 0.5 Ca 0.5 MnO 3 , or Pr 0.67 Ca 0.33 MnO 3 . 
     
     
         4 . The semiconductor structure of  claim 1 , further comprising an oxide material over at least one surface of the crystalline PCMO material. 
     
     
         5 . The semiconductor structure of  claim 4 , wherein the oxide material comprises a rare earth metal oxide. 
     
     
         6 . The semiconductor structure of  claim 5 , wherein the rare earth metal oxide comprises a material selected from the group consisting of zirconia (ZrO x ), yttrium oxide (YO x ), erbium oxide (ErO x ), gadolinium oxide (GdO x ), lanthanum aluminum oxide (LaAlO x ), and hafnium oxide (HfO x ). 
     
     
         7 . The semiconductor structure of  claim 1 , further comprising at least one electrode over the substrate. 
     
     
         8 . The semiconductor structure of  claim 7 , further comprising at least another electrode over the crystalline PCMO material. 
     
     
         9 . The semiconductor structure of  claim 1 , wherein the semiconductor structure comprises a variable resistance memory cell. 
     
     
         10 . The semiconductor structure of  claim 1 , wherein the crystalline PCMO material is formed by a process wherein exposing the surface of the substrate to a manganese-containing precursor comprises exposing the surface of the substrate to a manganese-containing precursor comprising a cyclopentadienyl ligand (Cp). 
     
     
         11 . The semiconductor structure of  claim 10 , wherein the crystalline PCMO material is formed by a process wherein exposing the surface of the substrate to a manganese-containing precursor comprising a cyclopentadienyl ligand comprises exposing the surface of the substrate to a material having the formula MnCp(CO) 3 . 
     
     
         12 . The semiconductor structure of  claim 10 , wherein the crystalline PCMO material is formed by a process wherein each of the manganese-containing precursor, the praseodymium-containing precursor, and the calcium-containing precursor comprise at least one compound having the formula M(MeCp) n , M(EtCp) n , M(iPrCp) n , M(tBuCp) n , M(Me 4 Cp) n , M(Me 5 Cp) n , and MCp(CO) n , wherein M represents manganese, praseodymium, or calcium and n represents a number of ligands used to balance the charge of the manganese, praseodymium, or calcium. 
     
     
         13 . The semiconductor structure of  claim 1 , wherein the crystalline PCMO material is formed by a process wherein exposing the surface of the substrate to the oxygen-containing precursor comprises exposing the surface of the substrate to at least one material selected from the group consisting of ozone, oxygen, and nitric oxide. 
     
     
         14 . The semiconductor structure of  claim 1 , wherein the crystalline PCMO material is formed by a process wherein exposing the surface of the substrate to the praseodymium-containing precursor comprises exposing the surface of the substrate to a praseodymium-containing precursor having the formula Pr(RCp) 3 , wherein R is an alkyl group. 
     
     
         15 . The semiconductor structure of  claim 1 , wherein the crystalline PCMO material is formed by a process wherein exposing the surface of the substrate to the calcium-containing precursor comprises exposing the surface of the substrate to a calcium-containing precursor having the formula Ca(RCp) 2 , wherein R is an alkyl group. 
     
     
         16 . The semiconductor structure of  claim 1 , wherein the crystalline PCMO material is formed by a process wherein exposing the surface of the substrate to each of the praseodymium-containing precursor, the calcium-containing precursor, the manganese-containing precursor, and the oxygen-containing precursor comprises separately exposing the surface of the substrate to each of the praseodymium-containing precursor, the calcium-containing precursor, the manganese-containing precursor, and the oxygen-containing precursor. 
     
     
         17 . A semiconductor structure comprising:
 at least one electrode on a substrate; and   a crystalline material overlying at least a portion of the substrate, the crystalline material comprising manganese, oxygen, praseodymium, and calcium, and formed by a process comprising:
 separately and repeatedly exposing the substrate at a temperature of less than about 450° C. to a manganese-containing precursor, an oxygen-containing gaseous precursor, a praseodymium-containing precursor, and a calcium-containing precursor, wherein the praseodymium-containing precursor comprises the formula Pr(RCp) 3 , wherein the calcium-containing precursor comprises the formula Ca(RCp) 2 , wherein Cp comprises a cyclopentadienyl ligand, and wherein each R independently comprises an alkyl group. 
   
     
     
         18 . The semiconductor structure of  claim 17 , further comprising an oxide material disposed over at least one surface of the crystalline material. 
     
     
         19 . The semiconductor structure of  claim 17 , further comprising at least another electrode disposed over the crystalline PCMO material. 
     
     
         20 . The semiconductor structure of  claim 17 , wherein the semiconductor structure comprises a variable resistance memory cell. 
     
     
         21 . A semiconductor structure comprising:
 a crystalline PCMO material overlying a substrate, the crystalline PCMO material formed by a process comprising:
 introducing a plurality of gaseous precursors to a surface of the substrate at a temperature of less than about 450° C. to form a plurality of manganese, oxygen, praseodymium, and calcium monolayers thereon, the plurality of gaseous precursors comprising a praseodymium-containing precursor comprising a cyclopentadienyl ligand (Cp) and a calcium-containing precursor comprising a cyclopentadienyl ligand (Cp); and 
 reacting the plurality of manganese, oxygen, praseodymium, and calcium monolayers to form a crystalline PCMO material without forming an amorphous PCMO material.