Short-channel schottky-barrier mosfet device and method of manufacture

Abstract

A MOSFET device and method of fabricating are disclosed. The present invention utilizes Schottky barrier contacts for source and/or drain contact fabrication within the context of a MOSFET device structure to eliminate the requirement for halo/pocket implants and shallow source/drain extensions to control short channel effects. Additionally, the present invention unconditionally eliminates the parasitic bipolar gain associated with MOSFET fabrication, reduces manufacturing costs, tightens control of device performance parameters, and provides for superior device characteristics as compared to the prior art.

1 . A MOSFET device comprising:
 a gate electrode on a semiconductor substrate;
 wherein the semiconductor substrate has a top surface, 
 wherein the semiconductor substrate includes channel dopants having a dopant concentration that varies significantly in a direction that is perpendicular to the top surface and is generally constant in a direction that is parallel to the top surface, 
   a source electrode and a drain electrode on the semiconductor substrate, wherein at least one of the source electrode and the drain electrode is metal; and   an interfacial layer disposed between the semiconductor substrate and the metal source electrode and further disposed between the semiconductor substrate and the metal drain electrode.   
     
     
         2 . The device of  claim 1  wherein the interfacial layer is in areas at least proximal to the gate electrode. 
     
     
         3 . The device of  claim 1  wherein an entire Schottky-like junction between the semiconductor substrate and at least one of the metal source electrode and the metal drain electrode incorporates the interfacial layer. 
     
     
         4 . The device of  claim 1  wherein at least in areas proximal to the gate electrode, a Schottky-like junction between the substrate and at least one of the metal source electrode and the metal drain electrode incorporates the interfacial layer. 
     
     
         5 . The device of  claim 1  wherein at least one of the metal source electrode and/or the metal drain electrode having the interfacial layer form a Schottky-like junction to the semiconductor substrate. 
     
     
         6 . The device of  claim 1  wherein the interfacial layer comprises an insulator. 
     
     
         7 . A MOSFET device, comprising:
 a gate electrode on a semiconductor substrate;
 wherein the semiconductor substrate has a top surface, 
 wherein the semiconductor substrate includes channel dopants having a dopant concentration that varies significantly in a direction that is perpendicular to the top surface and is generally constant in a direction that is parallel to the top surface, 
   an insulating layer disposed between the gate electrode and the semiconductor substrate;   a source electrode and a drain electrode on the semiconductor substrate, wherein at least one of the source electrode and the drain electrode is metal; and   an interfacial layer disposed between the semiconductor substrate and at least a portion of the metal source electrode and further disposed between the semiconductor substrate and at least a portion of the metal drain electrode.   
     
     
         8 . The device of  claim 7  wherein the interfacial layer is in areas at least proximal to the gate electrode. 
     
     
         9 . The device of  claim 7  wherein an entire Schottky-like junction between the semiconductor substrate and at least one of the metal source electrode and the metal drain electrode incorporates the interfacial layer. 
     
     
         10 . The device of  claim 7  wherein at least in areas proximal to the gate electrode, a Schottky-like junction between the substrate and at least one of the metal source electrode and the metal drain electrode incorporates the interfacial layer. 
     
     
         11 . The device of  claim 7  wherein at least one of the metal source electrode and/or the metal drain electrode having the interfacial layer form a Schottky-like junction to the semiconductor substrate. 
     
     
         12 . The device of  claim 7  wherein the interfacial layer comprises an insulator. 
     
     
         13 . The device of  claim 12  wherein an entire Schottky-like junction between the semiconductor substrate and at least one of the metal source electrode and the metal drain electrode incorporates the interfacial layer. 
     
     
         14 . The device of  claim 12  wherein at least in areas proximal to the gate electrode, a Schottky-like junction between the substrate and at least one of the metal source electrode and the metal drain electrode incorporates the interfacial layer. 
     
     
         15 . A MOSFET device, comprising:
 a gate electrode on a semiconductor substrate;
 wherein the semiconductor substrate has a top surface, 
 wherein the semiconductor substrate includes channel dopants having a dopant concentration that varies significantly in a direction that is perpendicular to the top surface and is generally constant in a direction that is parallel to the top surface, 
   an insulating layer disposed between the gate electrode and the semiconductor substrate;   a source electrode and a drain electrode on the semiconductor substrate, wherein at least one of the source electrode and the drain electrode is metal; and   a Schottky or Schottky-like junction formed by an interfacial layer disposed between the semiconductor substrate and at least a portion of the metal source electrode and-further disposed between the semiconductor substrate and at least a portion of the metal drain electrode.   
     
     
         16 . The device of  claim 15  wherein the interfacial layer is in areas at least proximal to the gate electrode. 
     
     
         17 . The device of  claim 15  wherein an entire Schottky-like junction between the semiconductor substrate and at least one of the metal source electrode and the metal drain electrode incorporates the interfacial layer. 
     
     
         18 . The device of  claim 15  wherein at least in areas proximal to the gate electrode, a Schottky-like junction between the substrate and at least one of the metal source electrode and the metal drain electrode incorporates the interfacial layer. 
     
     
         19 . The device of  claim 15  wherein at least one of the metal source electrode and/or the metal drain electrode having the interfacial layer form a Schottky-like junction to the semiconductor substrate. 
     
     
         20 . The device of  claim 15  wherein the interfacial layer comprises an insulator.