Silicon carbide semiconductor devices with a regrown contact layer

Abstract

Silicon carbide semiconductor devices having regrown layers and methods of fabricating the same in a self-aligned manner. According to one aspect of the invention, the method includes growing at least one layer of silicon carbide on a substrate, removing the device from a growth chamber to perform at least one processing step, and regrowing another layer of silicon carbide on the at least one layer. According to one embodiment of the invention, the regrown layer may be a heavily doped contact layer for the formation of low resistivity ohmic contacts.

1 - 27 . (canceled)  
   
   
       28 . A semiconductor device fabricated from Silicon Carbide (SiC), the device comprising: 
 a substrate;    at least one layer grown from SiC material on the substrate;    at least one other layer regrown from SiC material, wherein the at least one other layer includes a conductivity as regrown, free from any subsequent annealing, greater than the at least one layer; and    at least one ohmic contact.    
   
   
       29 . The device of  claim 28 , wherein the device is a radio frequency device.  
   
   
       30 . The device of  claim 28 , wherein the device is a radio frequency power device.  
   
   
       31 . The device of  claim 28 , wherein the device is a p-n junction.  
   
   
       32 . The device of  claim 28 , wherein the device is a transistor.  
   
   
       33 . The device of  claim 28 , wherein the device is a thyristor.  
   
   
       34 . A bipolar junction transistor fabricated from Silicon Carbide (SiC), the transistor comprising: 
 a substrate;    a collector layer formed from SiC material on the substrate and having a first conductivity type;    a base layer formed from SiC material on the collector layer and having a second conductivity type;    an emitter formed from SiC material on the base layer and having the first conductivity type; and    a regrown base contact layer formed from SiC material regrown on the base layer.    
   
   
       35 . The transistor of  claim 34 , comprising: 
 at least one ohmic contact.    
   
   
       36 . The transistor of  claim 34 , wherein the emitter is a mesa structure.  
   
   
       37 . The transistor of  claim 34 , wherein the transistor is a radio frequency power device.  
   
   
       38 . A Silicon Carbide (SiC) product, comprising: 
 a first bipolar device, formed on a first substrate, said device including a first layer and a third layer of SiC material, each having a first conductivity type, and a second layer of SiC material having a second conductivity type, said second layer being disposed between said first and third layers; and    a second bipolar device, formed on said substrate, said device including a fourth layer and a sixth layer of SiC material, each having a first conductivity type, and a fifth layer of SiC material having a second conductivity type, said fifth layer being disposed between said fourth and sixth layers,    wherein said first and second bipolar devices are substantially electrically isolated from one another.    
   
   
       39 . A product as set forth in  claim 38 , wherein each of said first bipolar device and said second bipolar device comprises a transistor.  
   
   
       40 . A product as set forth in  claim 38 , wherein each of said first bipolar device and said second bipolar device are formed on a semi-insulating substrate.  
   
   
       41 . A product as set forth in  claim 38 , wherein each of said first bipolar device and said second bipolar device comprises a device formed on a SiC substrate.  
   
   
       42 . A product as set forth in  claim 38 , wherein said first bipolar device comprises a first collector contact and said second bipolar device comprises a second collector contact electrically separated from said first collector contact.  
   
   
       43 . A product as set forth in  claim 42 , further comprising said first collector contact in substantial proximity to said second collector contact.  
   
   
       44 . A product as set forth in  claim 43 , wherein said first collector contact and said second collector contact are at least partially bounded by substantially a first plane substantially parallel to a second plane at least partially bounding at least one of said first, second, third, forth, fifth or sixth layers that comprise said substrate.  
   
   
       45 . A product as set forth in  claim 43 , wherein a portion of a collector layer has been rendered insulating.  
   
   
       46 . A method as set forth in  claim 38 , wherein said first bipolar device and said second bipolar device have substantially similar doping densities in at least one of their respective bases, collectors, emitters, or contacts.