Conversion of thin transistor elements from silicon to silicon germanium

Abstract

Embodiments of the present disclosure provide techniques and configurations associated with conversion of thin transistor elements from silicon (Si) to silicon germanium (SiGe). In one embodiment, a method includes providing a semiconductor substrate having a channel body of a transistor device disposed on the semiconductor substrate, the channel body comprising silicon, forming a cladding layer comprising germanium on the channel body, and annealing the channel body to cause the germanium to diffuse into the channel body. Other embodiments may be described and/or claimed.

What is claimed is: 
     
         1 . An apparatus comprising:
 a semiconductor substrate composed of silicon; and   a channel body of a transistor device disposed on the semiconductor substrate, the channel body comprising silicon germanium (SiGe) alloy, wherein the channel body includes a uniform distribution of germanium from an outer surface of the channel body to a center of the channel body that is consistent with diffusion of the germanium by anneal of a cladding layer comprising the germanium on a channel body material composed of silicon to form the SiGe alloy.   
     
     
         2 . The apparatus of  claim 1 , wherein a concentration of the germanium in the channel body decreases from the outer surface of the channel body to the center of the channel body. 
     
     
         3 . The apparatus of  claim 1 , wherein a concentration of the germanium in the channel body is substantially constant from the outer surface of the channel body to the center of the channel body. 
     
     
         4 . The apparatus of  claim 1 , wherein the transistor device is a dual-gate, tri-gate, or all-around gate transistor device. 
     
     
         5 . The apparatus of  claim 1 , wherein the channel body includes part of a fin structure formed from silicon of the semiconductor substrate. 
     
     
         6 . The apparatus of  claim 5 , wherein:
 the fin structure has a base portion adjacent to the semiconductor substrate, an end portion, and a middle portion disposed between the base portion and the end portion;   the base portion has a thickness that is greater than a thickness of the middle portion; and   the channel body has a thickness that is greater than a thickness of the middle portion.   
     
     
         7 . The apparatus of  claim 1 , wherein the channel body includes part of a nanowire structure. 
     
     
         8 . The apparatus of  claim 1 , wherein the channel body has a thickness that is twice a thickness of the cladding layer plus a thickness of the channel body material composed of silicon. 
     
     
         9 . The apparatus of  claim 1 , wherein the channel body has a faceted crystalline profile. 
     
     
         10 . The apparatus of  claim 1 , wherein the channel body is a first channel body of a first transistor, the apparatus further comprising:
 a second channel body disposed on the semiconductor substrate; and   electrically insulative material disposed on the semiconductor substrate between the first channel body and the second channel body.   
     
     
         11 . The apparatus of  claim 10 , wherein the first channel body and the second channel body are channel bodies of a plurality of p-channel bodies, the apparatus further comprising:
 a plurality of n-channel bodies disposed on the semiconductor substrate, wherein the plurality of n-channel bodies have a concentration of germanium that is different than a concentration of the germanium in the plurality of p-channel bodies.   
     
     
         12 . The apparatus of  claim 1 , further comprising:
 a gate oxide formed on the channel body; and   a gate electrode coupled with the channel body and configured to control flow of charge carriers in the channel body.   
     
     
         13 . A system comprising:
 a circuit board; and   a semiconductor die coupled with the circuit board, the semiconductor die including
 a semiconductor substrate composed of silicon, and 
 a channel body of a transistor device disposed on the semiconductor substrate, the channel body comprising silicon germanium (SiGe) alloy, wherein the channel body includes a uniform distribution of germanium from an outer surface of the channel body to a center of the channel body that is consistent with diffusion of the germanium by anneal of a cladding layer comprising the germanium on a channel body material composed of silicon to form the SiGe alloy. 
   
     
     
         14 . The system of  claim 13 , wherein:
 the channel body includes part of a fin structure formed from silicon of the semiconductor substrate;   the fin structure has a base portion adjacent to the semiconductor substrate, an end portion, and a middle portion disposed between the base portion and the end portion;   the base portion has a thickness that is greater than a thickness of the middle portion; and   the channel body has a thickness that is greater than a thickness of the middle portion.   
     
     
         15 . The system of  claim 13 , wherein the system is one of a laptop, a netbook, a notebook, an ultrabook, a smartphone, a tablet, a personal digital assistant (PDA), an ultra mobile PC, a mobile phone, a desktop computer, a server, a printer, a scanner, a monitor, a set-top box, an entertainment control unit, a digital camera, a portable music player, or a digital video recorder.