(Al, Ga, In) N-based compound semiconductor and method of fabricating the same

Abstract

Disclosed are a (Al, Ga, In) N-based compound semiconductor device and a method of fabricating the same. The (Al, Ga, In) N-based compound semiconductor device of the present invention comprises a substrate; a (Al, Ga, In) N-based compound semiconductor layer grown on the substrate; and an electrode formed of at least one material or an alloy thereof selected from the group consisting of Pt, Pd and Au on the (Al, Ga, In) N-based compound semiconductor layer. Further, the method of fabricating the (Al, Ga, In) N-based compound semiconductor device comprises the steps of growing a P layer including P type impurities in a growth chamber; discharging hydrogen and a hydrogen source gas in the growth chamber; lowering the temperature of the (Al, Ga, In) N-based compound semiconductor with the P layer formed thereon to such an extent that it can be withdrawn to the outside from the growth chamber; withdrawing the (Al, Ga, In) N-based compound semiconductor from the growth chamber; and forming an electrode of at least one material or an alloy thereof selected from the group consisting of Pt, Pd and Au on the P layer. According to the present invention, it is possible to sufficiently secure P type conductivity and obtain good ohmic contact characteristics without performing an annealing process. And, no ftrther annealing is necessary when Pt, Pd, Au electrode are used.

1 . A (Al, Ga, In) N-based compound semiconductor device, comprising: 
 a substrate;    a (Al, Ga, In) N-based compound semiconductor layer grown on the substrate; and    an electrode formed of at least one material or an alloy thereof selected from the group consisting of Pt, Pd and Au on the (Al, Ga, In) N-based compound semiconductor layer.    
   
   
       2 . The (Al, Ga, In) N-based compound semiconductor device as claimed in  claim 1 , wherein the electrode is formed by stacking Pt and Au, or Pd and Au.  
   
   
       3 . The (Al, Ga, In) N-based compound semiconductor device as claimed in  claim 1 , wherein the electrode is formed of an alloy of at least two selected from the group consisting of Pt, Pd and Au.  
   
   
       4 . A method of fabricating a (Al, Ga, In) N-based compound semiconductor device, comprising the steps of: 
 growing a (Al, Ga, In) N-based compound semiconductor layer (P layer) including P type impurities on a substrate in a growth chamber;    discharging hydrogen, ammonia and gas including hydrogen in the growth chamber;    lowering the temperature of the substrate with the P layer formed thereon to such an extent that the substrate can be withdrawn to the outside from the growth chamber;    withdrawing the substrate with the P layer formed thereon from the growth chamber; and    forming an electrode of at least one material selected from the group consisting of Pt, Pd and Au or an alloy thereof on the P layer.    
   
   
       5 . The method as claimed in  claim 4 , wherein the step of lowering the temperature is performed by means of water cooling or air cooling of the growth chamber.  
   
   
       6 . The method as claimed in  claim 4 , the step of lowering the temperature comprises the steps of: 
 maintaining the growth chamber under vacuum conditions; and    supplying a cooling gas into the growth chamber under vacuum conditions.    
   
   
       7 . A method of fabricating a P layer of a (Al, Ga, In) N-based compound semiconductor, comprising the steps of: 
 growing the P layer by supplying gases into a growth chamber while maintaining temperature in the growth chamber at a temperature for growth of the P layer of the (Al, Ga, In) N-based compound semiconductor;    stopping the supply of the gases after the growth of the P layer is completed;    discharging the gases existing in the growth chamber at a temperature higher than a temperature at which impurities in the P layer and hydrogen contained in the gases are bonded to each other; and    lowering the temperature of the P layer of the (Al, Ga, In) N-based compound semiconductor.    
   
   
       8 . The method as claimed in  claim 7 , wherein the temperature of the P layer is lowered by means of air cooling or water cooling.  
   
   
       9 . The method as claimed in  claim 7 , wherein the step of lowering the temperature of the P layer comprises the steps of: 
 maintaining the growth chamber under vacuum conditions; and    supplying a cooling gas into the growth chamber under vacuum conditions.    
   
   
       10 . The method as claimed  claim 7 , wherein the temperature for the growth of the P layer is in a range of 600 to 1,300° C.  
   
   
       11 . The method as claimed  claim 7 , wherein the temperature at which the gases existing in the growth chamber are discharged is in a range of 400 to 1,300° C.  
   
   
       12 . A P layer of a (Al, Ga, In) N-based compound semiconductor, said P layer being formed by growing the P layer while supplying gases into a growth chamber, stopping the supply of the gases after the growth of the P layer, completely discharging the gases existing in the growth chamber at a temperature higher than a temperature at which P type impurities and hydrogen are bonded to each other, and lowering the temperature of the P layer.