Semiconductor device, manufacturing method thereof, and semiconductor storage device

Abstract

A semiconductor device according to an embodiment includes an oxide film containing first element and a conductive film provided to be in contact with the oxide film, containing metal element and oxygen element, and having conductivity. A range of a volume density of the oxygen element in the conductive film is different between cases where the metal element are tungsten (W), molybdenum (Mo), titanium (Ti), chromium (Cr), vanadium (V), iron (Fe), copper (Cu), tantalum (Ta), or niobium (Nb).

1 . A semiconductor device comprising:
 an oxide film containing first element; and   a conductive film provided to be in contact with the oxide film, containing metal element and oxygen element, wherein   a volume density of the oxygen element in the conductive film is   less than 2.38×10 22  atoms/cm 3  when the metal element is tungsten (W),   less than 4.27×10 22  atoms/cm 3  when the metal element is molybdenum (Mo),   less than 2.28×10 22  atoms/cm 3  when the metal element is titanium (Ti),   less than 5.00×10 22  atoms/cm 3  when the metal element is chromium (Cr),   less than 4.23×10 22  atoms/cm 3  when the metal element is vanadium (V),   less than 4.84×10 22  atoms/cm 3  when the metal element is iron (Fe),   less than 2.82×10 22  atoms/cm 3  when the metal element is copper (Cu),   less than 3.32×10 22  atoms/cm 3  when the metal element is tantalum (Ta), and   less than 2.78×10 22  atoms/cm 3  when the metal element niobium (Nb).   
     
     
         2 . The device of  claim 1 , wherein the volume density of the oxygen element in the conductive film is 1.0×10 16  atoms/cm 3  or more. 
     
     
         3 . The device of  claim 1 , wherein an atom of the metal element is bounded with an atom of the oxygen element in the conductive film, and said atom of the oxygen element is bounded with an atom of the first element. 
     
     
         4 . The device of  claim 1 , wherein a binding energy between the metal element and an oxygen element is smaller than a binding energy between an oxygen element and the first element. 
     
     
         5 . The device of  claim 1 , further comprising a film on the conductive film, which contains metal element of a same type as or a different type from the metal element and has a lower oxygen concentration than the conductive film. 
     
     
         6 . A manufacturing method of a semiconductor device, comprising:
 forming an oxide film containing first element on a semiconductor substrate; and   forming a conductive film on the oxide film by using a material gas that contains metal element, a reducing gas that reduces the metal element, and a carrier gas that introduces the material gas into the substrate, wherein   at least one of the material gas, the reducing gas, and the carrier gas contains oxygen element, and   a temperature of the substrate in formation of the conductive film is higher than a sublimation temperature of metal oxide of the metal element.   
     
     
         7 . The method of  claim 6 , wherein forming the conductive film comprising:
 forming a first layer that is in contact with the oxide film and contains the metal element and the oxygen element; and   forming a second layer after forming the first layer, the second layer contains a metal element of a same type as or a different type from the metal element, and has a lower oxygen concentration than the first layer.   
     
     
         8 . The method of  claim 6 , wherein the metal element is tungsten (W), titanium (Ti), molybdenum (Mo), chromium (Cr), vanadium (V), iron (Fe), copper (Cu), tantalum (Ta), or niobium (Nb). 
     
     
         9 . The method of  claim 6 , wherein
 the material gas contains a tungsten compound,   the reducing gas contains hydrogen gas (H 2 ), nitrogen dioxide gas (NO 2 ), nitrous oxide gas (N 2 O), carbon monoxide gas (CO), oxygen gas (O 2 ), or ozone gas (O 3 ), and   the carrier gas contains argon gas (Ar), nitrogen gas (N 2 ), or carbon dioxide gas (CO 2 ).   
     
     
         10 . A semiconductor storage device comprising:
 a plurality of conductive films stacked apart from each other in a first direction;   a plurality of oxide films that are in contact with the conductive films in the first direction and are stacked via the conductive films;   a semiconductor layer penetrating through the conductive films and the oxide films in the first direction; and   a charge storage layer arranged between the semiconductor layer and the conductive films in a second direction crossing the first direction, wherein   the oxide films contain first element,   the conductive films contain metal element and oxygen element, and   a volume density of the oxygen element in the conductive film is   less than 2.38×10 22  atoms/cm 3  when the metal element is tungsten,   less than 4.27×10 22  atoms/cm 3  when the metal element is molybdenum,   less than 2.28×10 22  atoms/cm 3  when the metal element is titanium,   less than 5.00×10 22  atoms/cm 3  when the metal element is chromium,   less than 4.23×10 22  atoms/cm 3  when the metal element is vanadium,   less than 4.84×10 22  atoms/cm 3  when the metal element is iron,   less than 2.82×10 22  atoms/cm 3  when the metal element is copper,   less than 3.32×10 22  atoms/cm 3  when the metal element is tantalum, and   less than 2.78×10 22  atoms/cm 3  when the metal element is niobium.