Semiconductor device structures including energy barriers, and related methods

Abstract

A semiconductor device structure includes a transistor with an energy barrier beneath its transistor channel. The energy barrier prevents leakage of stored charge from the transistor channel into a bulk substrate. Methods for fabricating semiconductor devices that include energy barriers are also disclosed.

1 . A method for increasing charge duration within a channel of a transistor, comprising:
 forming an energy barrier consisting essentially of carbonated silicon on a surface of a base substrate;   forming a source region, a drain region, and a silicon channel of a transistor on the energy barrier; and   applying a charge to the channel.   
     
     
         2 . The method of  claim 1 , further comprising accessing the charge stored by the silicon channel. 
     
     
         3 . The method of  claim 1 , wherein forming an energy barrier comprises epitaxially forming the energy barrier. 
     
     
         4 . A semiconductor device, comprising:
 an energy barrier overlying a base substrate, the energy barrier consisting essentially of carbonated silicon; and   a transistor on the energy barrier and comprising:
 a source region; 
 a drain region; 
 a channel between the source region and the drain region and consisting of p-type silicon; and 
 a gate overlying at least portion of the channel. 
   
     
     
         5 . The semiconductor device of  claim 4 , wherein the semiconductor device comprises a dynamic random access memory device. 
     
     
         6 . The semiconductor device of  claim 4 , further comprising a gate dielectric positioned between the channel and the gate. 
     
     
         7 . The semiconductor device of  claim 4 , further comprising:
 sidewall spacers adjacent opposing sides of at least the gate; and   a cap on the gate.   
     
     
         8 . The semiconductor device of  claim 4 , wherein the carbonated silicon comprises up to about 1.4% carbon atoms. 
     
     
         9 . The semiconductor device of  claim 4 , wherein the energy barrier has a bandgap energy of greater than about 1.12 eV. 
     
     
         10 . The semiconductor device of  claim 4 , wherein the energy barrier exhibits a thickness within a range of from about 50 nm to about 150 nm. 
     
     
         11 . The semiconductor device of  claim 4 , wherein the channel consists of epitaxial, p-type silicon. 
     
     
         12 . The semiconductor device of  claim 4 , further comprising silicon dioxide between the channel and the gate. 
     
     
         13 . A semiconductor device structure, comprising:
 at least one transistor; and   an energy barrier consisting essentially of epitaxial carbonated silicon underlying an entirety of the at least one transistor.   
     
     
         14 . The semiconductor device structure of  claim 13 , wherein the at least one transistor comprises:
 a channel consisting essentially of epitaxial, p-type silicon on the energy barrier;   a source consisting essentially of epitaxial, n-type silicon on the energy barrier and adjacent a first side of the channel;   a drain consisting essentially of epitaxial, n-type silicon on the energy barrier and adjacent a second side of the channel; and   a gate overlying the channel.   
     
     
         15 . The semiconductor device structure of  claim 14 , further comprising:
 a dielectric material on the channel; and   spacers adjacent each side of the gate.   
     
     
         16 . The semiconductor device structure of  claim 13 , further comprising a semiconductive material directly under the energy barrier. 
     
     
         17 . The semiconductor device structure of  claim 13 , wherein the semiconductive material extends along an entirety of the energy barrier. 
     
     
         18 . The semiconductor device structure of  claim 13 , further comprising a dielectric material directly under the energy barrier. 
     
     
         19 . The semiconductor device structure of  claim 13 , wherein the energy barrier exhibits a thickness of up to about 150 nanometers. 
     
     
         20 . The semiconductor device structure of  claim 13 , wherein the energy barrier exhibits a bandgap energy of greater than or equal to about 1.5 eV.