SOI MOSFET having body contact for preventing floating body effect and method of fabricating the same

Abstract

An SOI MOSFET having a body contact for preventing the floating body effect is provided. The body contact is a trench perforating a body and a buried oxide layer to a semiconductor substrate. The trench is filled with a conductive material to electrically connect the body to the semiconductor substrate. Impurity ions are implanted into a predetermined region of the semiconductor substrate in contact with the lower portion of the body contact to form an ohmic contact. In the SOI MOSFET, an additional metal interconnection line is not needed to supply power to the body. Also, malfunction of a circuit due to stray capacitance of a contact can be prevented.

1 . A method of fabricating a SOI MOSFET comprising: 
 forming a buried oxide layer on a semiconductor substrate;    forming a silicon body on the buried oxide layer;    defining the silicon body as a channel region, a body contact, an isolation region, a field oxide layer region, a peripheral active region and etching the isolation region and the field oxide layer;    further etching the isolation region until the buried oxide layer is exposed;    forming oxide layers in the isolation region and the field oxide layer region;    forming a gate oxide layer on a predetermined region on the body and forming a gate on the gate oxide layer;    etching the semiconductor substrate from an upper part toward a lower part so that the body and the buried oxide layer are perforated to form a trench;    implanting predetermined impurity ions into a predetermined region of the semiconductor substrate to form an ohmic contact; and    filling the trench with a conductive material:    
     
     
         2 . The method of  claim 1 , wherein the predetermined region of the semiconductor substrate is the bottom of the trench.