Semiconductor-on-insulator (soi) substrates and semiconductor devices using void spaces

Abstract

An SOI substrate is fabricated by providing a substrate having a sacrificial layer thereon, an active semiconductor layer on the sacrificial layer remote from the substrate and a supporting layer that extends along at least two sides of the active semiconductor layer and the sacrificial layer and onto the substrate, and that exposes at least one side of the sacrificial layer. At least some of the sacrificial layer is etched through the at least one side thereof that is exposed by the supporting layer to form a void space between the substrate and the active semiconductor layer, such that the active semiconductor layer is supported in spaced-apart relation from the substrate by the supporting layer. The void space may be at least partially filled with an insulator lining.

1 . A semiconductor device, comprising: 
 a semiconductor substrate;    a device isolation layer on the semiconductor substrate; and    an active semiconductor layer spaced apart from the semiconductor substrate with a void space interposed therebetween, supported by the device isolation layer, and having a lattice constant close to that of the semiconductor substrate.    
     
     
         2 . The semiconductor device as claimed in  claim 1 , further comprising a gate electrode within the active layer or on the active layer remote from the semiconductor substrate.  
     
     
         3 . The semiconductor device as claimed in  claim 2 , wherein the gate electrode also extends on a side of the active semiconductor layer.  
     
     
         4 . The semiconductor device as claimed in  claim 3 , wherein the gate electrode covers a surface of the active semiconductor layer remote from the semiconductor substrate.  
     
     
         5 . The semiconductor device as claimed in  claim 1 , further comprising: 
 an insulating layer on a surface of the substrate facing the active semiconductor layer and on a surface of the active semiconductor layer facing the substrate.    
     
     
         6 . The semiconductor device as claimed in  claim 1 , wherein the semiconductor substrate is a Si substrate, and the active semiconductor layer is a Si epitaxial layer.