Assymetric hetero-doped high-voltage mosfet (ah2mos)

Abstract

An asymmetric heterodoped metal oxide (AH 2 MOS) semiconductor device includes a substrate and an insulated gate on the top of the substrate disposed between a source region and a drain region. On one side of the gate, heterodoped tub and source regions are formed. The tub region has dopants of a second polarity. A source region is disposed inside each tub region and has dopants of a first polarity opposite to the second polarity. On the other side of the gate, heterodoped buffer and drift regions are formed. The buffer regions comprise dopants of the second polarity. The drift regions are disposed inside the buffer regions and are doped with dopants of the first polarity. A drain n+ tap region is disposed in the drift region.

1 . A low-side asymmetric heterodoped metal oxide (AH 2 MOS) semiconductor device comprising:
 a substrate;   an insulated gate on the top of the substrate and disposed between a source region and a drain region;   on one side of the gate, heterodoped tub and source regions wherein the tub region has dopants of a second polarity and a source region is disposed inside the tub region and has dopants of a first polarity opposite to the second polarity;   on the other side of the gate, heterodoped buffer and drift regions wherein the buffer regions comprise dopants of the second polarity and the drift region is disposed inside the buffer region and comprises dopants of the first polarity; a drain tap region disposed in the drift region and comprising a heavily doped region of dopants of the first polarity; and   a conductor for connecting tap and source regions to a reference potential.   
   
   
       2 . The low-side asymmetric heterodoped metal oxide (AH 2 MOS) semiconductor device of  claim 1  wherein the reference potential is ground. 
   
   
       3 . A high-side asymmetric heterodoped metal oxide (AH 2 MOS) semiconductor device comprising:
 a substrate;   an insulated gate on the top of the substrate and disposed between a source region and a drain region;   on one side of the gate, heterodoped tub and source regions wherein the tub region has dopants of a second polarity and a source region is disposed inside the tub region and has dopants of a first polarity opposite to the second polarity;   on the other side of the gate, heterodoped buffer and drift regions wherein the buffer regions comprise dopants of the second polarity and the drift region is disposed inside the buffer region and comprises dopants of the first polarity;   a drain tap region disposed in the drift region and comprising a heavily doped region of dopants of the first polarity;   a conductor for connecting tap and source regions to a reference potential; and   an isolation ring comprising a junction structure of a first region of first polarity dopants and a second region of second polarity dopants disposed between the substrate and the heterodoped tub source, buffer and drift regions.   
   
   
       4 . The high-side asymmetric heterodoped metal oxide (AH 2 MOS) semiconductor device of  claim 3  wherein the device has three terminals including source, gate and drain terminals, and the source terminal is connected to the source regions and to the isolation ring. 
   
   
       5 . The high-side asymmetric heterodoped metal oxide (AH 2 MOS) semiconductor device of  claim 3  wherein the isolation ring junction structure comprises a first junction tub of dopants of a first polarity and a second junction tub of dopants of a second polarity with the boundaries of the first tub.