Semiconductor device

Abstract

A partial isolation insulating film provided between MOS transistors in an NMOS region and a PMOS region, respectively, has a structure in which a portion protruding upward from a main surface of an SOI layer is of greater thickness than a trench depth, namely, a portion (isolation portion) extending below the surface of the SOI layer, and the SOI layer under the partial isolation insulating film is of greater thickness than the isolation portion.

1 - 11 . (canceled)  
   
   
       12 . A semiconductor device comprising: 
 an SOI substrate including a substrate part serving as a base, a buried oxide film provided on said substrate part, and an SOI layer provided on said buried oxide film;    first and second element isolation insulating films provided in first and second regions on said SOI layer, respectively; and    a third element isolation insulating film provided between said first and second regions, wherein    said first element isolation insulating film has a partial trench isolation structure having said SOI layer provided thereunder,    said second and third element isolation insulating films at least partly include a full trench isolation structure reaching said buried oxide film through said SOI layer,    said first element isolation insulating film has a structure in which a protruding portion protruding upward from a main surface of said SOI layer is of greater thickness than an isolation portion extending below said main surface of said SOI layer,    said second element isolation insulating film only has said full trench isolation structure,    said third element isolation insulating film has a hybrid trench isolation structure including said full trench isolation structure and said partial trench isolation structure, said partial trench isolation structure being formed such that said protruding portion is of greater thickness than said isolation portion, and said under-isolation SOI layer is of greater thickness than said isolation portion, and    said protruding portion of said second element isolation insulating film and said protruding portion of said full trench isolation structure of said third element isolation insulating film are of smaller thickness than said protruding portion of said first element isolation insulating film.    
   
   
       13 . The semiconductor device according to  claim 12 , wherein 
 said first region is a region where an N-channel type MOS transistor is provided, and 
 said second region is a region where a P-channel type MOS transistor is provided.