Lanthanide oxide/zirconium oxide atomic layer deposited nanolaminate gate dielectrics

Abstract

The invention provides a laminated dielectric layer for semiconductor devices formed by a combination of ZrO 2 and a lanthanide oxide on a semiconductor substrate and methods of making the same. In certain methods, the ZrO 2 is deposited by multiple cycles of reaction sequence atomic layer deposition (RS-ALD) that includes depositing a ZrI 4 precursor onto the surface of the substrate in a first pulse followed by exposure to H 2 O/H 2 O 2 in a second pulse, thereby forming a thin ZrO 2 layer on the surface. After depositing the ZrO 2 layer, the lanthanide oxide layer is deposited by electron beam evaporation. The composite laminate zirconium oxide/lanthanide oxide dielectric layer has a relatively high dielectric constant and can be formed in layers of nanometer dimensions. It is useful for a variety of semiconductor applications, particularly for DRAM gate dielectric layers and DRAM capacitors.

1 - 41 . (canceled)  
   
   
       42 . A method of forming a composite laminate dielectric layer for a semiconductor structure, comprising 
 forming a first layer of a material selected from the group consisting of ZrO 2  and lanthanide oxide on a substrate; and    forming a second layer of material selected from the group consisting of ZrO 2  and a lanthanide oxide on the first layer of material, the second layer of material being different from the first layer of material.    
   
   
       43 . The method of  claim 42  wherein the first layer of material is ZrO 2  and the second layer of material is the lanthanide oxide.  
   
   
       44 . The method of  claim 42  wherein the first layer of material is the lanthanide oxide and the second layer of material is ZrO 2 .  
   
   
       45 . The method of  claim 42  wherein the lanthanide oxide is selected from the group consisting of Pr 2 O 3 , Nd 2 O 3 , Sm 2 O 3 , Gd 2 O 3 , Dy 2 O 3  and PrTixOy.  
   
   
       46 . The method of  claim 42  wherein depositing the ZrO 2  is performed at a temperature of about 230-325° C.  
   
   
       47 . The method of  claim 42  wherein the act of depositing the ZrO 2  oxide includes atomic layer deposition of a ZrI 4  precursor followed by oxidation with H 2 0/H 2 O 2 .  
   
   
       48 . The method of  claim 47  wherein the atomic layer deposition is performed at a temperature of about 230-325° C.  
   
   
       49 . The method of  claim 47  wherein the atomic layer deposition is performed at a temperature of about 272-275° C.  
   
   
       50 . The method of  claim 42  wherein the lanthanide oxide layer is formed by electron beam evaporation of the lanthanide oxide.  
   
   
       51 . The method of  claim 42  wherein the ZrO 2  oxide layer is formed by atomic layer deposition of a ZrI 4  precursor followed by oxidation with H 2 0/H 2 O 2  and the lanthanide oxide layer is formed by electron beam evaporation of the lanthanide oxide.  
   
   
       52 . The method of  claim 42  wherein the ZrO 2  layer is formed to a thickness of about 2-5 nm.  
   
   
       53 . The method of  claim 42  wherein the lanthanide oxide layer is formed to a thickness of about 2-10 nm.  
   
   
       54 . The method of  claim 42  wherein the ZrO 2  layer is formed to a thickness of about 2-5 nm and the lanthanide oxide layer is formed to a thickness of about 2-10 nm.