Semiconductor device

Abstract

A semiconductor chip includes a first circuit and a second circuit having different reference potentials. A first potential which is a reference potential of the first circuit is applied to the semiconductor chip through any of plural lead terminals, and a second potential which is a reference potential of the second circuit is applied to the semiconductor chip through any of plural lead terminals. A substrate of the semiconductor chip has a structure in which a buried insulating layer and a semiconductor layer of a first conductivity type are laminated on a semiconductor substrate such as a SOI substrate. A fixed potential is applied to the semiconductor substrate through a die pad and a lead terminal for a substrate potential. The fixed potential is applied to the semiconductor chip through a different route from the reference potential of the first circuit and the reference potential of the second circuit.

What is claimed is: 
     
         1 . A semiconductor device comprising:
 a substrate comprising a semiconductor substrate, an insulating layer over the semiconductor substrate, and a semiconductor layer over the insulating layer;   a first circuit over the semiconductor layer;   a second circuit arranged side by side over the semiconductor layer and electrically insulated from the first circuit;   a first inductor located between the first circuit and the second circuit in plan view and located over the semiconductor layer in sectional view, the first inductor being electrically connected to the first circuit;   a second inductor located between the first circuit and the second circuit in plan view and located over the first inductor in sectional view, the second inductor being electrically connected to the second circuit;   wherein a potential of the semiconductor substrate is independent from both of a reference potential of the first circuit and a reference potential of the second circuit.   
     
     
         2 . The semiconductor device according to  claim 1 ,
 wherein the reference potential of the first circuit is supplied from outside of the semiconductor substrate,   wherein the reference potential of the second circuit is supplied from outside of the semiconductor substrate, and   wherein the potential of the semiconductor substrate is supplied from outside of the semiconductor substrate.   
     
     
         3 . The semiconductor device according to  claim 1 ,
 wherein the reference potential of the first circuit is supplied from outside of the semiconductor substrate,   wherein the reference potential of the second circuit is supplied from outside of the semiconductor substrate, and   wherein the potential of the semiconductor substrate is in floating.   
     
     
         4 . The semiconductor device according to  claim 1 , further comprising:
 a first well constituting a part of the first circuit; and   a second well constituting a part of the second circuit,   wherein the first well comprises a first edge facing the second well,   wherein the second well comprises a second edge facing the first well, and   wherein a thickness of the semiconductor substrate is less than a distance between the first edge of the first well and the second edge of the second well.   
     
     
         5 . The semiconductor device according to  claim 1 ,
 wherein a thickness of the semiconductor substrate is equal to or less than 100 μm.   
     
     
         6 . The semiconductor device according to  claim 1 ,
 wherein a difference between the reference potential of the first circuit and the reference potential of the second circuit is equal to or greater than 100 V.