Semiconductor device with gate dielectric containing mixed rare earth elements

Abstract

A semiconductor device, such as a transistor or capacitor, is provided. The device includes a substrate, a gate dielectric over the substrate, and a conductive gate electrode film over the gate dielectric. The gate dielectric includes a mixed rare earth nitride or oxynitride film containing at least two different rare earth metal elements.

1 . A semiconductor device comprising:
 a substrate;   a gate dielectric over the substrate, wherein the gate dielectric comprises a mixed rare earth nitride or oxynitride film containing at least two different rare earth metal elements and having a thickness between about 5 and about 40 angstrom; and   a conductive gate electrode film over the gate dielectric.   
     
     
         2 . The device of  claim 1 , wherein the at least two different rare earth metal elements are selected from Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. 
     
     
         3 . The device of  claim 1 , wherein the device is a transistor. 
     
     
         4 . The device of  claim 1 , wherein the device is a capacitor. 
     
     
         5 . The device of  claim 1 , further comprising an interface layer between the substrate and the gate dielectric, wherein the interface layer comprises a nitride layer or an oxynitride layer. 
     
     
         6 . A semiconductor device comprising:
 a substrate;   a gate dielectric over the substrate, wherein the gate dielectric comprises a mixed rare earth oxynitride film of the following formula:
   RE1 x RE2 y O m N n    
   
       wherein RE1 and RE2 are different and are each rare earth metal elements selected from Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, and wherein x, y, m, and n are non-zero numbers, the mixed rare earth oxynitride film having a thickness between about 5 and about 40 angstrom; and
 a conductive gate electrode film over the gate dielectric. 
 
     
     
         7 . The device of  claim 6 , wherein the device is a transistor. 
     
     
         8 . The device of  claim 6 , wherein the device is a capacitor. 
     
     
         9 . The device of  claim 6 , further comprising an interface layer between the substrate and the gate dielectric, wherein the interface layer comprises an oxide layer, a nitride layer, or an oxynitride layer. 
     
     
         10 . A semiconductor device comprising:
 a substrate;   a gate dielectric over the substrate, wherein the gate dielectric comprises a mixed rare earth nitride film of the following formula:
   RE1 x RE2 y N n    
   
       wherein RE1 and RE2 are different and are each rare earth metal elements selected from Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, and wherein x, y, and n are non-zero numbers; and
 a conductive gate electrode film over the gate dielectric. 
 
     
     
         11 . The device of  claim 10 , wherein the device is a transistor. 
     
     
         12 . The device of  claim 10 , wherein the device is a capacitor. 
     
     
         13 . The device of  claim 10 , further comprising an interface layer between the substrate and the gate dielectric, wherein the interface layer comprises an oxide layer, a nitride layer, or an oxynitride layer.