Monolithic MOSFET and schottky diode for mobile phone boost converter

Abstract

A cell phone has a plurality of interconnected electronic components for performing the electrical functions of the phone. A DC/DC converter provides an operating voltage which is applied to power supply terminals of the plurality of interconnected electronic components. The DC/DC converter uses a monolithic semiconductor device containing a power metal oxide semiconductor field effect transistor (MOSFET) and Schottky diode. The semiconductor device has the lateral diffused MOSFET formed on a surface of the semiconductor device. The MOSFET is formed with a plurality conduction fingers. The Schottky diode is also formed on the surface of the semiconductor device and integrated between the plurality of conduction fingers of the MOSFET. The drain of the MOSFET is connected to the anode of the diode on the surface of the monolithic semiconductor device.

1 . A monolithic semiconductor device, comprising: 
 a lateral double diffused metal oxide semiconductor field effect transistor (LDMOSFET) formed with a plurality conduction fingers on a surface of the monolithic semiconductor device; and    a diode formed on the surface of the monolithic semiconductor device and integrated between the plurality of conduction fingers of the LDMOSFET, wherein a first conduction terminal of the LDMOSFET is connected to a first terminal of the diode on the surface of the monolithic semiconductor device.    
   
   
       2 . The monolithic semiconductor device of  claim 1 , further including a semiconductor package enclosing the LDMOSFET and diode and having four external connections.  
   
   
       3 . The monolithic semiconductor device of  claim 2 , wherein the semiconductor package has a first connection coupled to a first conduction terminal of the LDMOSFET.  
   
   
       4 . The monolithic semiconductor device of  claim 3 , wherein the semiconductor package has a second connection commonly coupled to a second conduction terminal of the LDMOSFET and a first terminal of the diode.  
   
   
       5 . The monolithic semiconductor device of  claim 4 , wherein the semiconductor package has a third connection coupled to a second terminal of the diode.  
   
   
       6 . The monolithic semiconductor device of  claim 5 , wherein the semiconductor package has a fourth connection coupled to a control terminal of the LDMOSFET.  
   
   
       7 . The monolithic semiconductor device of  claim 1 , wherein the plurality of conduction fingers of the LDMOSFET include a repeating pattern of source and drain conduction fingers.  
   
   
       8 . The monolithic semiconductor device of  claim 7 , wherein drift regions of the diode are integrated between the repeating pattern of source and drain conduction fingers of the LDMOSFET.  
   
   
       9 . A semiconductor package, comprising a monolithic semiconductor device including a lateral double diffused metal oxide semiconductor field effect transistor (LDMOSFET) formed on a surface of the monolithic semiconductor device and a diode formed on the surface of the monolithic semiconductor device and integrated between a plurality of conduction fingers of the LDMOSFET.  
   
   
       10 . The semiconductor package of  claim 9 , wherein a first connection of the semiconductor package is coupled to a first conduction terminal of the LDMOSFET.  
   
   
       11 . The semiconductor package of  claim 10 , wherein a second connection of the semiconductor package is commonly coupled to a second conduction terminal of the LDMOSFET and a first terminal of the diode.  
   
   
       12 . The semiconductor package of  claim 11 , wherein a third connection of the semiconductor package is coupled to a second terminal of the diode.  
   
   
       13 . The semiconductor package of  claim 12 , wherein a fourth connection of the semiconductor package is coupled to a control terminal of the LDMOSFET.  
   
   
       14 . The semiconductor package of  claim 9 , wherein the plurality of conduction fingers of the LDMOSFET include a repeating pattern of source and drain conduction fingers.  
   
   
       15 . The semiconductor package of  claim 14 , wherein drift regions of the diode are integrated between the repeating pattern of source and drain conduction fingers of the LDMOSFET.  
   
   
       16 . A monolithic semiconductor device, comprising: 
 a lateral double diffused metal oxide semiconductor field effect transistor (LDMOSFET) formed with a plurality conduction fingers on a surface of the monolithic semiconductor device; and    a diode formed on the surface of the monolithic semiconductor device and integrated between the plurality of conduction fingers of the LDMOSFET.    
   
   
       17 . The monolithic semiconductor device of  claim 16 , further including a semiconductor package enclosing the LDMOSFET and diode and having four external connections.  
   
   
       18 . The monolithic semiconductor device of  claim 17 , wherein the semiconductor package has a first connection coupled to a first conduction terminal of the LDMOSFET.  
   
   
       19 . The monolithic semiconductor device of  claim 18 , wherein the semiconductor package has a second connection commonly coupled to a second conduction terminal of the LDMOSFET and a first terminal of the diode.  
   
   
       20 . The monolithic semiconductor device of  claim 19 , wherein the semiconductor package has a third connection coupled to a second terminal of the diode.  
   
   
       21 . The monolithic semiconductor device of  claim 20 , wherein the semiconductor package has a fourth connection coupled to a control terminal of the LDMOSFET.  
   
   
       22 . The monolithic semiconductor device of  claim 16 , wherein the plurality of conduction fingers of the LDMOSFET include a repeating pattern of source and drain conduction fingers.  
   
   
       23 . The monolithic semiconductor device of  claim 22 , wherein drift regions of the diode are integrated between the repeating pattern of source and drain conduction fingers of the LDMOSFET.  
   
   
       24 . A method of making a monolithic semiconductor device, comprising: 
 forming a lateral double diffused metal oxide semiconductor field effect transistor (LDMOSFET) with a plurality conduction fingers on a surface of the monolithic semiconductor device; and    forming a diode on the surface of the monolithic semiconductor device integrated between the plurality of conduction fingers of the LDMOSFET.    
   
   
       25 . The method of  claim 24 , further including forming the plurality of conduction fingers of the LDMOSFET as a repeating pattern of source and drain conduction fingers.  
   
   
       26 . The method of  claim 25 , further including integrating drift regions of the diode between the repeating pattern of source and drain conduction fingers of the LDMOSFET.